社団法人日本機械学会Acta Medica Okayama0387-5016605741994狭い円環状空隙に溶融プラスチックを流入させた場合の凝固特性323330ENHideoInabaHideakiIkegamiKoichiOzakiThis paper deals with solidification and flow characteristics of high-density polyethylene plastics as polymer plastics in a narrow annular cavity cooled on an inner circular tube. The experiments are carried out with various parameters (plastics temperature, flow velocity of the plastics and cooling surface temperature). The obtained results show that the solidification layer formation of polymer plastics is affected by flow behavior and viscosity of molten polymer plastics. The useful dimensionless equations for predicting the amount of polymer plastics and the time of finishing the injection of the polymer plastics into the cavity are derived as a function of Reynolds number, cooling temperature ratio and Stefan number.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016605781994流動過冷却水および水溶液の管内凍結発生限界に及ぼす諸因子の影響218225ENHideoInabaKengoTakeyaSupercooling characteristics of water and water solution in a forced flow were investigated both experimentally and analytically. The critical conditions of ice nucleation in a cooled circular tube were examined for five sets of tube dimensions under various Reynolds numbers. It was found that the critical degree of supercooling based on the inner wall temperature was independent of Reynolds number in a laminar flow region. However, in a turbulent flow region, it decreased with increasing Reynolds number. An ice nucleation model for the flowing supercooled liquid was developed to predict the critical conditions of ice formation, in which the effects of the flow and temperature conditions, tube dimensions and solute mass fraction were taken into consideration. Nondimensional correlation equations for the critical condition of ice formation were derived in laminar and turbulent flow regions as a function of some nondimensional parameters obtained by analyzing the ice nucleation model.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016605721994低温潜熱物質を分散体としたO/W型エマルションを用いた蓄冷システムに関する基礎研究 : 第2報,コイル状2重管式熱交換器を用いた場合の流動および蓄冷特性324331ENHideoInabaShin-ichiMoritaThe thermal properties of the test O/W-type emulsion were described in the first report. This paper dealts with flow and cold heat-storage characteristics of the oil (tetradecane, C_<14>H_<30>, freezing point 278.9 K) /water emulsion as a latent heat-storage material having a low melting point. A coiled double-tube heat exchanger was used for the cold heat-storage experiment. The pressure drop, the heat-transfer coefficient and the finishing time of cold heat storage in the coiled tube were measured as experimental parameters. It was clarified that the flow behavior of the emulsion as a non-Newtonian fluid played an important role in cold heat storage. The useful nondimensional correlation equations for the additional pressure loss coefficient, the heat-transfer coefficient and the finishing time of the cold heat storage were derived in terms of Dean number and heat capacity ratio.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016605801994管内流動過冷却水中の球形氷粒子挙動173180ENHideoInabaKengoTakeyaNumerical calculation of behavior of a spherical ice particle (motion, melting and solidification) in flowing supercooled water inside a cooled circular tube was performed. By assuming that the single ice particle moved from its position on the upper or lower cooling surface in fully developed laminar flow, the variation of ice particle radius during the moving process could be calculated under various Reynolds numbers for water, initial ice particle radii and cooling conditions. For the particle motion in flowing water, the numerical results were in good agreement with the measurements obtained from visualization using paraffin particles (density : 926 kg/m^3). It was found that the initial ice particle radius, Reynolds number of water and the cooling wall temperature exerted pronounced effects on the ice particle radius at the tube exit ; however the inlet temperature of the flowing water had little effect on the radius at the tube exit.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016605711994ワイヤーコイルを用いた円管内熱伝達促進と流動抵抗軽減に関する基礎研究 : 第2報,ワイヤーコイルによる管内熱伝達の評価と最適配置283288ENHideoInabaKoichiOzakiShinichiKanaokaAn experimental investigation on wire-coil-inserted tubes as a turbulence promoter has been undertaken for enhancement of heat transfer and reduction of flow friction factor in water flow. The performance of wire-coil-inserted tubes has been evaluated in terms of two different criteria based on the fixed flow rate and pumping power. In order to enhance the heat transfer rate and reduce the How friction factor, some experiments have been carried out wherein coils with various lengths were partially inserted into the tube. As a result, it is noted that there is an optimum arrangement of the wire coil in the tube for the enhancement of heat transfer and the reduction of friction factor.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016605801994低凝固点油滴の凝固を利用した潜熱蓄冷に関する基礎研究 : 第1報,低温水溶液中を浮上するテトラデカン油滴の流動および凝固特性258265ENHideoInabaKenjiSatoFlow and solidification characteristics of tetradecane droplets [melting point of 5.8℃, latent heat of 229.1 kJ/kg, density of 770 kg/m^3 (at 6℃) ] ascending in ethlene glycol water solution of 30 weight percent at low temperature were investigated experimentally in order to examine the possibility of a liquid-liquid or liquid-solid direct-contact-type latent cold heat storage system. A new type of solidification rate meter is proposed in the present study. As a result, some interesting freezing behaviors of droplets were observed by the visualization technique. From the measurements of solidification rate of tetradecane droplets, the relationships between the solidification rate and some experimental parameters were clarified.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016605691994ワイヤーコイルを用いた円管内熱伝達促進と流動抵抗軽減に関する基礎研究 : 第1報,ワイヤーコイルによる管内流動抵抗および熱伝達特性240247ENHideoInabaKoichiOzakiShinichiKanaokaExperimental studies have been carried out on heat-transfer enhancement and flow-drag reduction in a tube by means of wire coil insert. Heat-transfer rate and pressure-drop data of tubes with wire coil inserts have been taken under various experimental conditions of wire coil diameter and pitch, water flow rate and heating-surface temperature. The performance of these tubes with wire coil inserts has been evaluated concerning the increase of heat-transfer rate and flow resistance. The useful nondimensional correlations of heat-transfer rate and flow-resistance factor have been derived as functions of Reynolds number and wire coil pitch-to-diameter ratio.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615811995矩形流路内における溶融高密度ポリエチレンの流動・凝固現象223230ENHideoInabaKoichiOzakiHideakiIkegamiSolidification and flow characteristics of molten high-density polyethylene flowing in a rectangular cavity having a cooling wall are investigated experimentally. Experiments are carried out under various parameters of molten polyethylene temperature, flow velocity of the polyethylene, cooling wall temperature and the thickness of the cavity. The obtained results reveal that the solidification layer formation of the polyethylene is affected by flow behavior, polyethylene temperature and cooling wall temperature. The useful non-dimensional equations, which predict the amount of polyethylene and the time required for injecting the polyethylene into the cavity, are derived as a function of Reynolds number, cooling temperature ratio and Stefan number.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016595671993比較的浅い底面加熱を受ける上部開放矩形くぼみに球状粒子を一段充填した場合の共存対流熱伝達286294ENHideoInabaKoichiOzakiShigeruNozuHeat transfer measurements were performed during forced and natural mixed convections of a rectangular open cavity which was packed with spherical particles arranged in a one step orthorhombic array. Air flowing over the cavity was heated from the bottom surface of the cavity via the particle layer. Three kinds of spherical particles having almost the same diameter of 10 mm and different thermal conductivities were used as the spherical packing material. The cavity depth was varied from 0 mm (flat plate) to 10 mm. The particles suppressed the air motion near the heating surface and decreased the heat transfer coefficient. In the case of particles having large thermal conductivity, those particles behaved as an extended heat transfer surface and turbulence promoter so that the heat transfer coefficient was enhanced. The Nusselt number ratio as a dimensionless heat transfer coefficient was expressed in terms of Reynolds number, ratio of particle diameter to depth of the cavity and modified Prandtl number.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615831995低温潜熱物質を分散体としたO/W型エマルションを用いた蓄冷システムに関する基礎研究 : 第3報,空気-エマルション直接接触熱交換法による放冷特性365372ENHideoInabaShin-ichiMoritaThe thermal properties, the flow and cold heat-storage characteristics of the O/W-type emulsion were reported in the first and the second report, respectively. This paper deals with cold heat-release characteristics of the oil (tetradecane, C_<14>H_<30>, freezing point 278.9K)/water emulsion as a latent heat-storage material having a low melting point. An air-emulsion direct contact heat exchange method was selected for the cold heat-release from the solidified emulsion layer. The temperature effectiveness, the sensible heat release time and the latent heat release time were measured as experimental parameters. The useful nondimensional correlation equations for those parameters were derived in terms of nondimensional emulsion level expressed the emulsion layer dimensions, Reynolds number for air flow, Stefan number and heat capacity ratio.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016595671993放射熱エネルギ利用融雪材の融雪機構解明に関する研究278285ENHideoInabaHideoOtakeThe melting behavior of a snow layer was investigated experimentally and numerically for the case where the snow layer was melted from the upper surface using radiative heat absorption material (black calcium carbonate powder). The experiments and calculation were carried out under various conditions of sprinkling density of radiative heat absorption material, environmental temperature, radiation heat intensity and snow density. It was clarified that an optimum density of the absorption material existed for the enhancement of snow layer melting. With low sprinkling density of the absorption material, the exposed snow surface, due to the gathering effect of the absorption material, brought about a decrease of the snow melting rate. On the other hand, with high sprinkling density of the absorption material, the snow melting rate also decreased due to increase of the thermal insulation effect of the absorption material. Useful nondimensional correlation equations for snow melting were derived in accordance with the ranges of various parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615851995昇華蒸発現象を利用した除霜に関する基礎研究 : 第1報,強制対流下にさらされた水平霜層の昇華蒸発挙動230237ENHideoInabaSeishiImaiThe present paper deals with a new defrosting measure employing the frost sublimation phenomenon. The present experimental study has focused on the mass transfer rate of a horizontal frost layer in a moist air flow. It is understood that the mass flux of the frost layer is increased by both the increase of the mass transfer coefficient resulting from the air velocity and the increase of the water vapor mass concentration difference between the frost surface and main moist air flow. The nondimensional correlation equations of mass transfer, heat transfer and finishing time of the defrost have been derived with a function of various parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016595671993熱放射による傾斜霜層の融解に関する基礎研究270277ENHideoInabaHideoOtakeAkihiroShigemoriThis paper deals with a new defrosting method in which a frost layer is melted by radiative heat energy as an energy source. The far-infrared radiative heat energy having a maximum wavelength of 5.5 μm is selected as the optimum radiative heat energy source for melting of the inclined frost-layer. The inclined frost-layer melting experiments using the radiative heat energy with a discharge of melted water on a cooling copper plate are carried out under various environmental parameters (inclination angle of frost-layer, radiative heat energy flux, air temperature, cooling brine temperature) including porosity of frost-layer as a frost structural factor. The dimensionless correlation equations which predict the time taken for complete frost-layer melting are derived as a function of various nondimensional frost-layer melting parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016595671993静止水の過冷却現象に及ぼす諸因子の影響255262ENHideoInabaKengoTakeyaSupercooling characteristics in quiescent bulk water enclosed in a circular tube were investigated on a basic level through numerous experiments. In the experiments, three kinds of water with different specific resistances were used as the test samples and their freezing temperatures were measured. The critical degree of supercooling depended on the property of the heat transfer surface and the cooling rate, and it became larger for a smoother surface and a higher cooling rate. It was found that the specific resistance of the water had little effect on the critical degree of supercooling . However, the insoluble particles included in the water greatly affected the ice nucleation in the supercooled water and the size effect of the insoluble particles was found to become important in the range of 0.1-1.0 μm in particle radius. For particle radii larger than this range, the critical degree of supercooling was independent of the size, while below this range it sharply increased with a decrease in the particle size.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615861995昇華蒸発現象を利用した除霜に関する基礎研究 : 第2報,強制対流下にさらされた水平霜層に放射熱エネルギを照射した場合の昇華蒸発挙動295302ENHideoInabaSeishiImaiThe present paper deals with the new defrosting method by means of the frost sublimation phenomenon with radiant heat. The frost sublimation phenomenon occurs at the triple point of water (273.16 K, 610.5 Pa). The present experimental study focuses on the mass transfer rate of a horizontal frost layer exposed to a moist air flow and radiant heat. It is understood that the mass flux of the frost layer increases with increase of the water vapor mass concentration difference between the frost and main moist air flow, the main air flow velocity, and the infrared radiant heat intensity. The non-dimensional correlation equations of mass transfer, heat transfer and finishing time of the defrosting process have been derived taking into account various parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016595651993低温潜熱物質を分散体としたO/W型エマルションを用いた蓄冷システムに関する基礎研究 : 第1報,熱物性の評価282289ENHideoInabaShin-ichiMoritaShigeruNozuThis paper deals with thermal properties of oil (tetradecane, C_<14>H_<30>, melting point of 278.9K) / water emulsion as a latent heat storage material having a low melting point. The measured results of the physical properties of the test emulsion, i.e., thermal conductivity, specific heat, latent heat and density, were discussed for the temperature region of solid and liquid phases of the dispersion material (tetradecane). It was clarified that Eucken's equation could be applied to the estimation of thermal conductivity of the emulsion. Moreover it was established that tetradecane as the dispersion material exhibited a supercooling phenomenon which influenced the thermal properties. Useful correlation equations of thermal properties for the emulsion were proposed in terms of temperature and concentration ratio of the emulsion constituents.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615881995低温潜熱物質を芯物質とする微細カプセル混合水を用いた蓄放冷システムに関する基礎研究 : 第2報,コイル状2重管式熱交換器を用いた場合の流動および蓄冷熱特性266273ENHideoInabaShin-ichiMoritaThe physical properties of the test fine capsulated latent heat-storage material-water mixture were described in the first report. This paper deals with flow and cold heat-storage characteristics of the fine capsulated latent heat-storage material-water mixture as a latent heat-storage material having a low melting point of the core material (pentadecane, C_<15>H_<32>, freezing point 283.1 K). A coiled double-tube heat exchanger was used for the cold heat-storage experiment. The pressure drop, the heat-transfer coefficient and the finishing time of cold heat-storage in the coiled tube were measured as experimental parameters. It was clarified that the flow behavior of the fine capsulated latent heat-storage material-water mixture as a non-Newtonian fluid played an important role in cold heat-storage. The nondimensional correlation equations for the additional pressure loss coefficient, the heat-transfer coefficient and the finishing time of the cold heat-storage were derived in terms of Dean number and heat capacity ratio.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016595601993静止状態におけるバルク状水および水溶液の過冷却現象に影響を及ぼす諸因子の効果200207ENHideoInabaKengoTakeyaShigeruNozuSupercooling characteristics on still bulk water and several kinds of water solutions were investigated experimentally. The test fluids, which were sandwiched in between two immiscible liquids in a glass tube, were set in a constant low-temperature room, and its freezing temperature was measured. It was found that the critical degree of supercooling for the water increased with decreasing test fluid volume, V, and was proportional to the logarithm of V. However, the critical degree of supercooling for the water solutions varied with the type of solute, and for each solute, it increased with increasing solute concentration. The critical degree of supercooling for the water solution was larger than that for the water by about 0〜4 K. The increment supercooling, which depended on the type of solute, could be explained by the equilibrium freezing point depression, an increase in the viscosity and solute/water interactions. In addition, the present data for the water solutions were correlated with dimensionless parameters which expressed these effects.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615891995流動水溶液による管内連続製氷に関する基礎研究198205ENHideoInabaSatoshiMiyaharaKengoTakeyaFundamental study was carried out concerning the possibility of continuous slurry ice making using D-sorbitol solution flowing in cooled circular glass and stainless-steel tubes. In the present experiment, the supercooling condition of the flowing water solution was released by injecting ice nucleation material such as fine ice particles into the cooled tube. As a result, three types of operating conditions in the pipe, that is supercooling, continuous ice making and ice blockage, were classified. It was clarified that the ice making efficiency was increased with an increase in the nondimensional cooling ratio, and with decreasing of Reynolds number and the concentration of the water solution. The efficiency of continuous ice making in the cooled tube was greater by 2〜5 times than that of continuous ice making outside the tube under the by supercooling condition. A nondimensional correlation equation for the ice making efficiency was derived as a function of some nondimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016595601993比較的大きな球状粒子を充填した下面加熱・上面冷却を受ける水平粒子層の対流熱伝達192199ENHideoInabaKoichiOzakiShigeruNozuHeat transfer and pressure drop measurements were performed in a forced convection of air flow through a rectangular duct packed with spherical particles, which had upper cooled and lower heated surfaces. Four kinds of particles with different diameters and thermal conductivities were used as the packing materials. The effects of solid boundaries on fluid motion and heat transfer were discussed. The heat transfer rate from the surfaces was promoted by a thermal dispersion effect caused by a fluid mixing motion. However, it was decreased in the vicinity of the near-wall region due to low effective thermal conductivity and weak fluid mixing motion. It was clarified that the ratio of the thermal boundary layer thickness developed from the heat transfer surfacec to the size of the near-wall region was important in order to reduce the heat transfer data. Nondimensional heat transfer correlation equations were derived, using parameters expressing the average characteristics of the porous bed packed with spherical particles.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016585551992水平霜層の熱放射による上部融解に関する基礎研究149157ENHideoInabaHideoOtakeShigeruNozuThe paper presents a new defrosting method in which a frost layer is melted away by radiative heat as a heat source. The optical characteristics of the horizontal frost layer (reflectivity, transmissivity, absorptivity) are obtained under various frost melting conditions. The far-infrared lamp having a maximum wavelength of 5.5μm is selected as the optimum radiative heat source for the melting frost. The frost layer melting experiments with radiative heat are carried out under various exvironmental parameters (radiative heat flux, environmental air temperature, air humidity, cooling brine temperature) and frost structural factors of density and porosity. The useful dimensionless equations for predicting the time taken for complete frost melting are derived as a function of various frost melting parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615891995界面活性剤添加水溶液の管内流動抵抗軽減と熱伝達206212ENHideoInabaKoichiOzakiNaotoHarukiHideakiAsanoThe reduction characteristics of flow resistance and heat transfer of water solution flow with the surfactant (Cetyltrimethyl-ammonium Bromide) in tubes were investigated experimentally. The flow resistance and heat transfer of Water solution flow with the surfactant were markedly reduced as compared with those of pure water flow. Useful nondimensional correlative equations of flow resistance and heat transfer were derived in terms of various non-dimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615921995低温潜熱物質を芯物質とする微細カプセル混合水を用いた蓄放冷システムに関する基礎研究 : 第3報,空気-微細カプセル化潜熱物質混合水の直接接触熱交換法による放冷熱特性216223ENHideoInabaShin-ichiMoritaThis paper deals with cold energy release characteristics of a fine capsulated latent-heat storage material-water mixture as a latent-heat-storage material having a low melting point of the core material (pentadecane, C_<15>H_<32>, freezing point 283.1 K). A direct-contact heat exchange method for an air-fine capsulated latent heat storage material-water mixture was selected to investigate the cold energy release characteristics from the mixture layer including the solidified core latent-heat-storage materials. The temperature effectiveness, the sensible-heat release time and the latent-heat release time were measured as experimental parameters. Useful nondimensional correlation equations for those parameters were derived in terms of nondimensional level of the mixture layer dimension, Reynolds number for air flow, Stefan number and heat capacity ratio.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016585531992水和塩の過冷却状態を利用した潜熱蓄熱に関する研究 : 第1報, 酢酸ナトリウム3水和塩の過冷却状態を含む物性の評価204212ENHideoInabaHideoOtakeShigeruNozuTakeyukiFukudaThis study focusses on a new type of latent heat storage material (hydrate sodium acetate, CH_3 COONa・3H_2O, normal melting point of 58°), which stably maintains the supercooling condition with the aid of some additions. This phase-change material can store latent heat (liquid-solid phase) under the supercooling condition from -10°to 58°without the help of thermal insulation for a long time. This article discusses measured results of physical properties of this phase-change material, i. e., thermal conductivity, spcific heat, latent heat, density, kinematic viscosity and crystal growth speed under various temperatures (solid and liquid phases), including the supercooling condition.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016615851995低温潜熱物質を芯物質とする微細カプセル混合水を用いた蓄放冷システムに関する基礎研究 : 第1報,微細カプセル化潜熱物質混合水の物性評価253260ENHideoInabaShin-ichiMoritaThis work deals with physical properties of a fine capsulated latent heat storage material-water mixture. The fine capsulated material consists of pentadecane (C_<15>H_<32>, melting point of 283.1 K) as the core latent heat storage material and melamine resin as the coating material. The measured results of the physical properties of the test mixture, i. e. , density, latent heat and viscosity, were analyzed for the temperature region of solid and liquid phases of the core latent heat storage material (pentadecane). It was clarified that the additional properties law could be applied to the estimation of density and latent heat of the fine capsulated latent heat storage material. Moreover it was found that the viscosity of the test mixture increased with an increase in concentration of the fine capsulated latent heat storage material. Useful correlation equations of viscosity for the fine capsulated latent heat storage material-water mixture were derived in terms of temperature and concentration.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016625931996低凝固点油滴の凝固を利用した潜熱蓄冷に関する基礎研究 : 第2報, 低温水溶液中を浮上するテトラデカン油滴の凝固および熱伝達の無次元整理式325332ENHideoInabaKenjiSatoThe latent cold heat storage system using the direct-contact freezer with tetradecane oil and ethylene glycol aqueous solution as the latent cold heat storage material and the cold heat transfer medium, respectively, was proposed in a previous paper [Inaba and Sato, Trans. JSME, 60-580 (1994), 4236.]. In this report, in order to obtain practical data for industrial application, nondimensional analysis of the solidification rate of the tetradecane oil droplets and the overall heat transfer coefficient in the freezer was carried out. In this system, the tetradecane oil droplets change from liquid to solid state during ascension in the cold heat transfer medium. Therefore, liquid-liquid and solid-liquid coexisting-type direct-contact heat transfer occurs between the tetradecane oil droplets and the aqueous solution. It can be considered that the flow pattern and heat transfer process are different for the liquid-liquid and the solid-liquid systems. The empirical equations of the solidification rate and the overall heat transfer coefficient were derived for the averaged values for the entire freezer. The optimum operating conditions at which the maximum solidification rate can be achieved were clarified.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016585521992傾斜く形潜熱蓄熱槽の蓄熱特性に関する数値計算232240ENHideoInabaShinichiMoritaMotohiroNagayaShigeruNozuMelting characteristics of a solid phase-change material in an inclined rectangulr heat-storage enclosure heated from one side are investigated numerically. It is found that a two-dimensional model simulates the melting behavior of the inclined rectangular heat storage, as compared with the results of a one-dimensional model. In each quasi-static step, steady-state natural convection in the liquid phase is calculated by directly solving the governing equation of motion with a finite difference technique. It is noted that the time development of the melting process depends strongly on the natural convection behavior, which is changed by the inclination angle and geometrical dimensions of the rectangular heat-storage enclosure.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016585481992流動過冷却水による連続製氷に関する基礎研究339346ENHideoInabaKengoTakeyaShigeruNozuBasic experiments were carried out concerning the possibility of continuous ice making in supercooled water in a forced flow. In the experiments, the critical conditions of ice formation and stability of supercooled water in cooled circular tubes were examined for four kinds of tube inner diameters under various Reynolds numbers. It was understood that two ice growth modes of annular ice and dendritic ice appeared in the cooling tube according to the degree of supercooling. Nondimensional correlation equations of supercooling for ice nucleation in laminar and turbulent flow regions were derived as a function of the nondimensional ratio of thermal boundary thickness to the pipe length, which length is defined as the distance from the position where the mixing average temperature of the flowing water becomes below freezing point to the pipe downstream end.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016625941996比較的浅い底面加熱を受ける上部開放矩形くぼみに球状粒子を一段充填した場合の共存対流熱伝達 : 第2報, くぼみ長さの効果330337ENKoichiOzakiHideoInabaForced-natural-mixed convection heat transfer characteristics of a one-stage spherical particle layer in an air flow are investigated experimentally. The one-stage spherical particle layer is provided in a rectangular cavity having a heating bottom surface and is installed at the lower part of a rectangular air channel. Three types of spherical particles, which have almost the same diameter (about 10 mm) but different thermal conductivities, are tested. The cavity length is varied from 19.6 mm to 90 mm, and the cavity depth is varied between 0 mm and 10 mm. The variation of the heat transfer coefficient with the length of the heating surface can be explained by the flow behavior around the particle layer ; that is, the case of the zero cavity depth, the flow is suppressed by the particles within about three rows from the leading edge. Therefore, the heat transfer coefficient increases with a derease in the length of the heating surface. In the case with a shorter heating surface (about twice the diameter of the particle), a considerable increase in the heat transfer coefficient is achieved because the flow from the upstream runs through the particle layer. In the case of the cavity depth having almost the same value as the diameter of the particles, air flows over the particle layer and air near the cavity bottom is almost still. In this case, a decrease of the length of the heat transfer surface decreases the extent of the flow in the depth direction, and the heat transfer coefficient is also decreased. The heat transfer coefficient can be expressed as a nondimensional heat transfer correlation, where the effects of the cavity length, the cavity depth, the air velocity and the temperature difference between the air and the bottom surface of the cavity are taken into consideration.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016625961996比較的大きな球状粒子を充填した下面加熱・上面冷却を受ける水平粒子層の対流熱伝達 : 第2報, 充填層厚さの影響208215ENKoichiOzakiHideoInabaConvection heat transfer and pressure drop measurements were performed with a rectangular duct, having a cooled upper and a heated lower surface, which was packed with spherical particles. Air was used as the test fluid and four kinds of spherical particles having different diameters and thermal conductivities were used as the packing materials. The ratio of the diameter of the spherical particle to the distance between the cooled and the heated surfaces, d/H, was varied from 0.173 to 1. The thermal conductivity of the particle layer was also measured under the still air condition. The thermal conductivity of the particle layer was not affected by the value of d/H. In the case of the one stage arrangement of spherical particles (d/H = 1), the flow resistance took on a remarkably small value compared with the flow resistance of a homogeneous spherical particle layer. Moreover the flow resistance of the particle layer formed with some layers of particles was able to be predicted by combining the flow characteristic of the one stage particle layer and that of the homogeneous spherical particle layer. The heat transfer coefficient of the particle layer was larger than that of turbulent air flow on a flat plate. At a constant superficial air velocity, there existed the value of d/H which gave a maximum value of the average heat transfer coefficient. Nondimensional heat transfer correlation equations were derived in terms of parameters expressing the average characteristics of the spherical particle layers.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016666502000衡突噴流による円環状霜層の昇華特性149156ENHideoInabaAkihikoHoribeNaokiTakamotoYoshiakiKawakamiSeishiImaiThe present paper has dealt with a new method of defrosting by using the frost sublimation phenomenon which occurs below the triple point of water (273.16K, 610.5Pa). The present experimental study has focussed to examine the mass transfer of the annular frost layer developed on a cooling pipe exposed to an impinging jet flow. Morphology of the frost layer during sublimating was observed by using a CCD camera. It was understood that the mass flux of the frost layer increased with increasing the jet flow velocity and the difference of the mass concentration of water vapor between the frost surface and the inpinging jet flow. The nondimensional correlation equations of mass transfer of defrosting were derived as functions of various parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016625961996平板状形状安定化潜熱蓄熱材充填矩形蓄熱槽の非定常熱特性 : 蓄熱過程における諸因子の効果296303ENHideoInabaPingTuTransient characteristics of a ractangular latent heat storage vessel packed with shape-stabilized phase change (solid-liquid) material(PCM) are investigated numerically with the finite difference technique. It is found that the heat storage characteristics are greatly affected by the flow direction of the heat transfer medium since the natural and forced convection coexist in the heat storage vessel, That is, it is clarified that the effective thermal efficiency of the latent heat storage system is obtained with downward flow along a vertical PCM for the heat storage process. The effects of the inlet velocity and the inlet temperature of the heat transfer medium on transient heat characteristics of the latent heat storage system are also revealed in the present study.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016575351991非共沸混合冷媒R114/R113の水平二重管環状部における凝縮 : 圧力降下と物質伝達の整理224230ENShigeruNozuKouichiOzakiHideoInabaHiroshiHondaFrictional pressure gradient and vapor phase mass transfer correlations were developed for condensation of nonazeotropic refrigerant mixture R114/R113 in the annuli of horizontal double tubes with an enhanced inner tube. The frictional pressure gradient data were correlated fairly well by a previously developed empirical equation for condensation of pure refrigerants. The vapor phase mass transfer correlation was based on the previous results for turbulent flow in smooth and rough tubes with and without surface suction. For given conditions of vapor and tube wall, the heat transfer coefficient can be calculated by using the correlations for the vapor phase mass transfer coefficient and the heat transfer coefficient for the condensate film. The calculated values agree with the measured data to a mean absolute deviation of 14.3%.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016625991996平板状形状安定化潜熱蓄熱材充填矩形蓄熱槽の非定常熱特性 : 放熱過程における諸因子の効果250257ENHideoInabaPingTuTransient heat release characteristics of a rectangular latent heat storage vessel packed with shape-stabilized phase change (solid-liquid) material (PCM) are investigated numerically with the finite difference technique. It is found that the heat release characteristics are greatly affected by the flow direction of the heat transfer medium since natural and forced convections coexist in the heat storage vessel. It is clarified that the thermal efficiency of the latent heat storage system is obtained by an upward flow along the vertical PCM for heat release process The effect of the inlet velocity and the inlet temperature of heat transfer medium and the dimensions of the phase change material on transient heat release characteristics of the latent heat storage system are also revealed in the present study.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016575341991非共沸混合冷媒R114/R113の水平二重管環状部における凝縮 : 実験結果249256ENShigeruNozuKouichiOzakiHideoInabaHiroshiHondaLocal heat transfer and pressure drop measurements were made during condensation of a nonazeotropic refrigerant mixture R114/R113 in the annuli of horizontal double-tube condensers. The inner tube was a 19.1mm o.d. corrugated copper tube with soldered wire fins on the outer surface. The outer tubes were smooth tubes with inside diameter D_i of 29.9 and 25.0mm. The pressure drop and the heat transfer coefficient based on the bulk vapor-to-wall temperature difference were considerably smaller for R114/R113 than for R113. The vapor phase mass transfer coefficient β_n was higher for larger test fluid mass velocity G and D_i. At constant values of G and D_i, β_n was higher for larger condensation mass flux. The radial distribution of the vapor temperature was affected by the vapor velocity, becoming flatter at the outer part of the annulus and steeper near the liquid-vapor interface as the vapor velocity increased.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016626021996低凝固点油滴の凝固を利用した潜熱蓄冷熱に関する基礎研究 : 第3報, 粒状凝固潜熱蓄冷熱材と温空気の直接接触熱交換による放冷熱特性172179ENHideoInabaKenjiSatoThis paper deals with the cold latent heat energy release characteristics of direct-contact heat exchange between the solidified oil droplets [tetradecane, CH_3(CH_2)_<12>CH_3, melting point5.8℃] and hot air. Hot air is injected into the solidified oil droplet-water mixture layer from the distributor with a number of small circular nozzles. The solidified oil droplet-water mixture layer is fluidized by the air bubbles ascending in the layer, and the air bubbles are cooled from the layer by the direct-contact heat exchange. This paper deals with the characteristics of temperature and humidity of the outlet air from the layer, and time history of the cold heat energy release. The experiments were performed with respect to several experimental parameters, i. e., air flow rate, air temperature and humidity, and the amount of oil droplets and water in the mixture layer. Finally, some empirical correlations for the outlet air temperature and humidity and the finishing time of cold latent heat release were derived in terms of various nondimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016575331991下向き凝縮面の伝熱促進に関する研究 : 凝縮面を傾斜させた場合の実験結果195201ENShigeruNozuHiroshiHondaTsutomuKobayashiHideoInabaExperiments were perfomed to study the effect of surface inclination on condensation heat transfer from downward-facing horizontal surfaces. A smooth surface and two low-finned surfaces with a length of 50mm were tested for condensation of R-113. The angle of inclination from the horizontal φ ranged from 0 to 90 deg. For the smooth surface, the heat tranfer coefficient α first decreased with the increasing of φ, then took a minimum near 5 deg, and then increased monotonically with further increasing φ. For the low-finned surfaces, α increased sharply with φ in the range of 0 to 30 deg, and then increased moderately with further increasing φ. The heat tranpfer coefficient for the better performing finned surface was 2.5, 9 and 12 times the smooth surface value for φ=0, 10 and 90 deg., respectively.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016626031996固体境界壁近傍の影響を考慮した球状粒子充填層の強制対流熱伝達の数値解析モデルの提案172179ENKoichiOzakiHideoInabaA simple model for the heat transfer and pressure drop characteristics in a layer of spherical particles is proposed in the present study. The layer of spherical particles bounded by two parallel boundary walls is considered to consist in two regions, one of which is the near-wall region of particles within a half-diameter of the spherical particle from the wall, and the other is the core region of particles over a half-diameter of the spherical particle away from the wall. The characteristics of the near-wall region, such as the permeability, the Forchheimer coefficient, and the thermal dispersion coefficient, are determined based on the experimental data for a one-stage spherical particle layer. For the core region, the permeability and the Forchheimer coefficient are evaluated using previous correlations for a homogeneous spherical particle layer, while the thermal dispersion coefficient is modified from that given by the previous correlation for a homogeneous spherical particle layer to include the effect of the thermal conductivity ratio of the spherical particle and the fluid. The effective thermal conductivity of the layer of spherical particles is assumed to be constant in the present model. The validity of the model is proved by comparing the results of this analysis with experimental results under various conditions.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636071997衝突噴流下にさらされた水平霜層の昇華蒸発に関する実験的研究254261ENHideoInabaSeishiImaiThe present study deals with a new defrosting measure by means of the frost sublimation phenomenon. The frost sublimation phenomenon occurs below the triple point of water (273.16K, 610.5Pa). The present experimental study has focused on the mass transfer rate of a horizontal frost layer exposed to an impinging jet flow. It is understood that the mass flux of the frost layer increases with increasing jet flow velocity and water vapor mass concentration difference between the frost and an impinging jet flow. The nondimensional correlation equations of mass transfer, heat transfer and finishing time of defrosting have been derived as a function of various parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636071997低凝固点油滴の凝固を利用した潜熱蓄冷熱に関する基礎研究 : 第4報, 低温水溶液中を浮上するテトラデカン油滴の流動および凝固特性に関する数値計算267274ENHideoInabaKenjiSatoThis paper proposes a numerical calculation method to predict solidification characteristics of paraffin oil droplets (tetradecane, CH_3(CH_2)_12CH_3,melting point is 5.8℃, diameter is 4〜6mm) ascending in a cold water solution (mixture of ethylene glycol [CH_2OH・CH_2OH] and water, temperature is -2〜-10℃) by buoyancy. The oil droplets start to ascend with several initial velocities and initial temperatures (10〜60℃) in the water solution. The oil droplets are decelerated by hydraulic resistance of the water solution. The water solution flows vertically downward at a low velocity of 0.1 m/s. The temperature of the oil droplet decreases due to direct-contact heat transfer with the cold water solution, and the oil droplet starts to solidify when its surface temperature reaches the freezing point. The solidification rate of the oil droplet is calculated based on a combination of flow behavior and solidification characteristics of the oil droplet. As a result, the motion of the oil droplet, the completion height and time for solidification are determined. The parameters used are the diameter, initial velocity and initial temperature of the oil droplet, and temperature and velocity of water solution.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016565261990雪層中の水分飽和度測定に関する基礎研究226230ENHideoInabaHideoOtakeThis reports two measuring methods of the water saturation rate in a snow layer melted from above, investigated, which is important to explain the water permeability in the snow layer. One of the methods is to measure the electric resistance of the wet snow existing between two electrodes which are supplied with a high-frequency alternating current. This method is suitable for measuring the water saturation rate of the wet snow at a local part of the snow layer during long periods of time. The other methed is to measure the gradation of the infrared photograph by the use of the thermal emissivity difference between water and snow. The calibration curve between the gradation of infrared photograph and the water saturation rate is examined in the preliminary run. This measuring method is useful to obtain information on the water saturation rate of the wet snow in a two-dimensional plane. The obtained results show that these two measuring methods are convenient for predicting the water movement behavior in the snow layer.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636091997球カプセル化潜熱蓄熱体を充填した小型潜熱蓄熱槽の蓄熱特性に関する数値解析274281ENKoichiOzakiHideoInabaAkihiroShigemoriWe numerically investigate heat storage characteristics of a small heat storage vessel packed with phase-change material (PCM) encapsulated into a spherical hollow. The heat storage vessel is dealt with as a porous medium, and the flow of the working fluid is analyzed two-dimensionally using the modified Darcian momentum equation which takes into account both the buoyancy effect and the channeling effect. The heat transfer in the encapsulated PCM is analyzed using a one-dimensional heat conduction model. It is clarified that the completion of the heat storage process is delayed by natural convection, since the incoming hot working fluid flows mainly near the upper part of the vessel. It is also found that the nonhomogeneity near the boundary walls prolongs the heat storage process since it decreases the flow resistance near the walls and promotes a bypass flow near the upper wall due to the natural convection. A nondimensional equation is derived for the time taken to complete heat storage, where the Fourier number is expressed as a function of the modified Stefan number, the modified Reynolds number and the modified Grashof number.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016565231990寒冷地における塩水太陽池の熱特性評価234241ENHideoInabaTakeyukiFukudaA one-dimensional numerical model which simulates the dynamic thermal performance of stratified salt-gradient solar pond is described. The model simulates the thermal performance in the upper convective layer, the nonconvective layer and the lower convective layer in a cold climate. In addition to the energy flux in the solar pond, the model simulates the varying ice thickness appearing in the upper convective layer during the winter season. From the results, it is noticed that it is important to maintain the optimum thickness of the nonconvective layer and the clearness of the upper convective layer for the high thermal efficiency of the salt-gradient solar pond.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016676542001氷水スラリーと温空気との直接接触熱交換による放冷に関する基礎研究210217ENShigeoAoyamaHideoInabaThis paper has dealt with direct contact heat exchange characteristics between ice water slurry (average ice particle diameter : 3.10 mm) and hot air bubbles. The hot air bubbles ascending in the layer fluidized the ice water slurry layer, and the bubbles were cooled down directly by the ice water slurry. The following results were obtained from the experiment. In case of ice water slurry layer, the hot air bubbles fluidized the layer in earlier stage and heat exchange performance was higher than using only ice particles layer. The maximum temperature efficiency increased as Reynolds number Re increased because fluid in the layer became active and kept at the fixed value in the region of Re >__=900. Dehumidity efficiency increased as modified Stefan number and Re increased since the heat capacity of inlet air and heat transfer coefficient increased. Some empirical correlations for temperature efficiency, dehumidity efficiency and the completion time of latent cold heat release were derived in terms of various nondimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636071997低凝固点油滴の凝固を利用した潜熱蓄冷熱に関する基礎研究 : 第5報, 低温水溶液流速を変化させた場合の浮上油滴の流動および凝固特性275282ENHideoInabaKenjiSatoFlow and solidification characteristics of tetradecane droplets [melting point of 5.8℃, latent heat of 229.1 kJ/kg, density of 770 kg/m^3 (at 6℃)] ascending in ethylene glycol water solution of 30 mass percent at low temperature were investigated experimentally in order to examine the existence of a liquid-liquid or liquid-solid direct-contact-type latent cold heat storage system. Some interesting freezing behaviors of droplets were observed under the conditions of various water solution flow velocities and oil-injection nozzle diameters by the visualization technique. Eventually, the relation-ships between the solidification rate and some experimental parameters were clarified.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636081997冷熱エネルギー輸送用界面活性剤添加低温水の管内流動抵抗と熱伝達特性208215ENHideoInabaNaotoHarukiInvestigation of characteristics of cold water pipe flow with surfactant is important to develop a cold heat energy transport system. Both flow drag and heat transfer reductions by the Toms effect occur due to a rod-like micell structure of surfactant. When a counter-ion (sodium salicylate) was added to water solution containing of dodecyltrimethylammonium chloride (DATC) surfactant in the present study, the rod-like micell structure of DTAC was formed by connection of spherical micells of DTAC. Moreover, the reduction characteristics of flow resistance and heat transfer were influenced by the amount of the counter-ion. Useful nondimensional correlative equations for flow resistance and heat transfer are derived in terms of various nondimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636091997衝突噴流下の水平霜層に放射熱エネルギを照射した場合の昇華蒸発促進効果205212ENHideoInabaSeishiImaiThe present paper deals with a new defrosting method based on the frost sublimation phenomenon. The focus of the present experimental study is the sublimation mass transfer of a horizontal frost layer exposed to impinging jet flow and radiant energy. It is found that the mass flux of the frost laye rincreases with increasing jet flow velocity and the radiant heat intensity. Non-dimensional correlations for mass transfer, heat transfer and defrosting completion time have been derived in terms of various parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636101997形状安定化球状潜熱蓄熱体を用いた流動層型潜熱蓄熱槽の流動および蓄熱特性291298ENHideoInabaAkihikoHoribeKouichiOzakiTakayukiYamazawaThis paper deals with fluidization and heat storage characteristics of shape-stabilized latent heat storage particles packed into a fluidized bed-type heat storage vessel. The shape-stabilized latent heat storage material consists of normal paraffin (pentacosane C_<25>H_<52>, latent heat 164 kJ/kg, melting point of 327.2 K) as a latent heat material, and polyethylene as a shape-stabilizing material. The pressure losses both on fluidized and on fixed particle layers were measured in order to investigate flow behavior in the heat storage vessel. It was found that the pressure loss of the fluidized particle layer was lower than that of the fixed particle layer. Furthermore, the effects of hot air flow rate, inlet air temperature and the amount of heat storage particles packed into the heat storage vessel on the completion time of the heat storage process were investigated. As a result, the nondimensional correlations for the completion time of the heat storage process were expressed in terms of nondimensional pumping power, the Stefan number and the ratio of the packed particle layer height to the diameter of the cylindrical heat storage vessel.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636141997沸騰凝縮現象を利用した形状安定化架橋ポリエチレン潜熱蓄熱材充填蓄熱槽の蓄熱特性182189ENHideoInabaZhongminLiThis paper deals with the experimental investigation of latent thermal energy storage characteristics of surface cross-linked form-stabilized high-density polyethylene pellets as a phase change material (PCM), using pool boiling and condensation of an ethylene glycol/water solution. The polyethylene pellets and heat transfer medium of ethylene glycol were mixed and poured into a cylindrical heat storage vessel. The heat transfer into the polyethylene pellets was mainly enhanced by the condensation of vapor bubbles of ethylene glycol/water solution which was heated by an electric heater set at the bottom of the vessel. The effects of heat input, the amount of PCM and ethylene glycol/water solution, and heater surface temperature on the heat storage characteristics were investigated. As a result, the nondimensional correlation equation of the completion time of the heat storage process was derived as a function of the nondimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016636161997形状安定化球状潜熱蓄熱粒子を用いた流動層型潜熱蓄熱槽の放熱特性207214ENHideoInabaAkihikoHoribeKoichiOzakiTakayukiYamazawaThis paper deals with heat energy release characteristics of shape-stabilized latent heat energy storage particles packed into a fluidized bed-type cylindrical heat energy storage vessel. This type of latent heat energy storage material consists of normal paraffin (pentacosane C_<25>H_<52>, latent heat : 164 kJ/kg, melting point of 327.2K) as a latent heat material, and polyethylene as a shape-stabilizing material. The effects of cold inlet air temperature and flow rate, and the amount of heat energy storage particles on the outlet air temperature from the heat storage vessel and the completion time of the heat energy release process were investigated. As a result, the non-dimensional correlations for the outlet air temperature from the heat storage vessel and the completion time of the heat energy release process were expressed in terms of non-dimensional pumping power, Stefan number and ratio of the packed particle layer height to the diameter of the cylindrical heat storage vessel.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016646181998傾斜配置した平板状形状安定化潜熱蓄熱材充填矩形蓄熱槽の蓄熱特性200207ENHideoInabaTuPingAkihikoHoribeKoichiOzakiThe present study deals with the heat storage characteristics of the inclined rectangular vessel packed with spape-stabilized paraffin plates as a latent heat storage material by numerical analysis. It was found that the heat storage characteristics were remarkedly affected by the inclination angle of the rectangular vessel and the heat transfer medium flow direction, due to the presence of natural convection in the fluid flow channel between the paraffin plates. Numerical results revealed flow patterns, temperature profiles and heat storage characteristics for various inclination angles, inlet velocities and temperatures of the heat transfer medium fluid, and widths of the fluid flow channel.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016646211998繊維質系流動抵抗軽減剤添加水の直管内流動抵抗および熱伝達特性178185ENHideoInabaNaotoHarukiAkihikoHoribeKoichiOzakiSome kinds of surfactants are useful to reduce flow drag in a turbulent pipe flow by Toms effect. However, it needs a lot of cost to make these surfactant harmless material to the environment. On the other hand, the fibrous substance such as pulp fibers and cellulose are harmless additives to the environment. This paper has dealt with the flow drag reduction and heat transfer characteristics of the water suspension flow mixed with fine fibers in a straight pipe. Measurements of velocity and temperature profile in a circular pipe flow were made in order to examine the flow drag and heat transfer characteristics of the turbulent and laminar flow. The nondimensional equations of pipe flow resistance and heat transfer were derived in terms of various nondimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016646271998フッ素系不活性液体を熱回収用媒体として用いた液-液直接接触熱交換に関する研究 : 温水中を降下するフッ素系不活性液滴群についての伝熱特性312319ENHideoInabaAkihikoHoribeKoichiOzakiNaokiYokoyamaThis paper deals with the heat transfer characteristics of a liquid-liquid direct contact operation in which a Perfluorocarbon (PFC) liquid is released in a hot water stream, a low-grade heat source such as urban sewage, for the purpose of heat recovery from it. The paper reports on a set of experiments in which a PFC liquid (1800 kg/m^3 at 20℃) was continuously injected from a single, downward-facing nozzle into a slow, upward flow of hot water to be disintegrated into droplets descending in, and thereby heated from the water flow. The results of the experiments show how the size distribution and the translational motions of the droplets affect the overall coefficient for the water-flow-to-droplets heat transfer and also the temperature effectiveness for the droplets.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016656311999架橋ポリエチレン粒子充填潜熱蓄熱槽の非定常放熱特性161168ENHideoInabaZhongminLiAkihikoHoribeKoichiOzakiTransient heat release characteristics of a latent heat storage vessel packed with surface cross-linked form stabilized high-density polyethylene pellets as a phase change material (PCM) have been investigated numerically and experimentally. The obtained results revealed the effects of the inlet velocity, the inlet temperature of ethylene glycol/water solution as a heat transfer medium, and the amount of the PCM on the heat release characteristics. As a result, the nondimensional correlation equation of the completion time of the heat release process was derived as a function of some nondimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016656351999直接接触熱交換法を用いた中温度潜熱蓄熱槽の放熱特性268275ENHideoInabaAkihikoHoribeKoichiOzakiKazuoEmotoHiroyukiKakiuchiExperiment has been performed of heat transfer characteristics of the middle temperature latent heat storage system of the direct-contact heat transfer by using m-E (meso-Erythritol, melting point of 119℃, latent heat of 375 kJ/kg) droplets as a latent heat storage material and silicone oil as a heat transfer medium. In the present study the liquid m-E was injected into the heat tranfer medium through a circular nozzle. The m-E droplets changed from liquid to solid phase during falling in the heat transfer medium at low temperature. From the measuring results of m-E droplet diameter, falling velocity, and solidification rate, the nondimensional empirical equations of the arithmetic mean diameter of the droplets and falling velocity, the solidification rate and the overall heat transfer coefficient were derived as a function of the characteristic arithmetic mean diameter, the terminal velocity, temperature and physical properties.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016656391999繊維系有機吸着剤の過渡的脱着特性239246ENHideoInabaKoichiOzakiAkihikoHoribeRikioShimoyamaTakahisaKidaAn experimental investigation was performed to determine the transient desorption characteristics of a fibrous type organic adsorbent, which was composed of the bridged complex of sodium polyacrylate as a new kind of adsorbent. The test fibrous adsorbent was packed in a cylindrical vessel, and dry air was passed through it. The experiments were conducted under various conditions of air velocity, temperature, relative humidity and vessel length. As a result, the pressure loss for the packed bed of the test fibrous adsorbent showed a similar tendency to that for the packed bed of spherical particles. The mass transfer data was correlated by the modified Sherwood number, the Reynolds number, the Schmidt number, the ratio of desorbed water vapor mass to fibrous adsorbent mass, the nondimensional temperature and the ratio of vessel length to fiber diameter. Fourier number for the completion times of adsorption processes were also correlated by Reynolds number, and the ratio of desorbed water vapor mass to fibrous adsorbent mass, the nondimensional temperature and the ratio of vessel length to fiber diameter.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016666452000温空気泡群と潜熱マイクロカプセルとの直接接触熱交換による蓄熱特性231238ENHideoInabaAkihikoHoribeHirofumiTsukamotoMyoung-JumKimThis paper has dealt with the heat storage characteristics of fine microcapsules packed with latent heat storage material in the water layer. The heat storage operation to the latent microcapsules was carried out using hot air bubbles by direct contact heat exchange. The microcapsule consists of n-paraffin as a core latent-heat storage material and melamine resin as a coating substance. The relation of the completion time of latent-heat storage to some parameters was examined experimentally. The non-dimensional correlation equations for the completion time of latent-heat storage process had were derived in terms of the ratio of water layer height to diameter of microcapsule, Reynolds number for air flow, Stefan number and modified Stefan number for absolute humidity of flowing air.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016666472000管内流動抵抗低減用界面活性剤を添加した低温水の曲がり管部における流動抵抗低減効果と熱伝達特性204211ENHideoInabaNaotoHarukiAkihikoHoribeThis paper has dealt with the flow resistance and heat transfer characteristics of flowing cold water with flow drag reduction additive in curved pipes. A cationic surfactant was used as the flow drag reduction additive. The flow drag resistance and the local heat transfer coefficient of cold water flow in some curved pipes were measured under the constant heat flux heating wall condition. It was found that the flow drag and heat transfer reduction effect by the surfactant was depended on the angle and curved ratio of the curved pipes. The nondimensional correlative equations of flow resistance and heat transfer coefficient of cold-water flow with the surfactant in the curved pipe were derived in terms of various nondimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016565301990水道分岐管の凍結挙動279284ENHideoInabaHideoOotakeThe formation of ice growth that occurs in branched pipes (branch angle θ=45° and 90°)containing water flow was investigated experimentally. The experiments were carried out under various experimental conditions over the range of Reynolds number (based on pipe i.d.) Re=420-12500 and cooling temperature ratios of the freezing parameter T(= T_f - T_w)/(T_∞ - T_f), T_f=0℃,T_w= cooling water pipe wall temperature, T_∞= flowing water temperature)=1.3-11.1. From the visualization of ice formation in the pipes, the branched pipe with flowing water was first blocked by ice formation : subsequently, the main pipe downstream of the branched portion was frozen off, and eventually the main pipe upstream of the branched portion was blocked by ice formation. As a result, freezing of the remaining water in the branched portion resulted in a pipe rupture at around the branched portion of the pipe. The transient behavior of ice formation, according to time proceeding, was expressed as a relationship between the pressure loss coefficient f and the Reynolds number Re for various cooling temperature ratios T. In addition, the critical condition of the complete ice blockage in branched pipes was obtained with experimental correlation equations in terms of T and Re.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016666512000着霜2円管の昇華による除霜挙動212219ENHideoInabaAkihikoHoribeYoshiakiKawakamiThe present paper has dealt with a new defrost measure by using sublimation phenomenon which occurs below the triple point of water (273.16 K, 610.5 Pa) The present experimental study has focused to examine the mass transfer of annular frost layers developed on two cooling horizonal pipes set in a vertical direction which was exposed to an impinging jet air flow. The morphology of the frost layer during sublimating was observed by using a CCD camera. The nondimensional correlation equations of mass transfer were derived as a function of various parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016666522000有機系収着剤を塗布したハニカム状収着エレメントの収着特性164171ENHideoInabaTakahisaKidaAkihikoHoribeMakotoKanedaThis paper has dealt with the sorption characteristics of honeycomb shape type sorbent element composed of new organic sorbent which was composed of the bridged complex of sodium polya-crylate. The transient experiments in which the moist air was passed into the honeycomb type sorbent element were conducted under various conditions of air velocity, temperature, relative-humidity and honeycomb length. As a result, the effective mass transfer coefficjent of the organic sorbent sorbing the water-vapor was non-dimensionalized as a function of Reynolds number, modified Stefan number and non-dimensional honeycomb length.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016676602001湿り空気による粉末状有機系収着剤流動層の水蒸気収着特性237244ENHideoInabaTakahisaKidaAkihikoHoribeKiyohiroKamedaTamioOkamotoJoung-kuenSeoThis paper has dealt with water vapor sorption characteristics of powder type organic sorbent bed by flowing a moist air. The powder type sorbent was fluidized in a rectangular vessel by the moist air flow. The sorption rate of vapor and the variation in temperature in the sorbent bed were measured under various air temperature and humidity conditions. It was found that the volume of the sorbent particles increased with in an increase in the amount of water vapor sorption. Finally, Sherwood number for water vapor mass transfer was expressed in terms of Reynolds number, the modified Stefan number, the ratio of sorbent particle diameter to fluidized bed height and Schmidt number.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016676602001平板状フィン付き加熱面を有する傾斜矩形潜熱蓄熱槽内の自然対流挙動245252ENHideoInabaKouichiMatsuoAkihikoHoribeThe present paper has dealt with the natural convection heat transfer in a melted liquid layer appeared in the inclined rectanglar latent heat storage vessel having one heating wall with plate fins. The effects of plate fin length, inclination angle of the rectangular vessel and heat wall temperature on the melting behavior of paraffin wax as a latent heat storage material. and natural convection heat transfer were investigated experimentally under a heat storage process. As a result, non-dimentional correlation equations of natural convection heat transfer were derived in terms of some non-dimentional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016686652002等熱流束加熱を受ける円管内を流動する潜熱マイクロカプセル混合水スラリーの熱伝達特性(数値計算による検討)161168ENHideoInabaMyoung-JunKimAkihikoHoribeThe present numerical analysis has been performed for obtaining the heat transfer characteristics of microencapsulated solid-liquid phase change material and water mixed slurry flow in a circular tube heated with constant wall heat flux. The energy equation was formulated by taking into consideration of the heat sink due to melting process and the heat transfer enhancement induced by the motion of microcapsules. The heat source function in the energy equation was derived from solutions for melting in a spherical latent heat material. The governing parameters were found to be latent heat material concentration, pipe diameter. microcapsule diameter, heat flux, and the slurry velocity. The numerical results revealed that mean heat transfer coefficient for latent microcapsule slurry was about 1.3〜1.8 times greater than that for the single phase of water.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016686662002ワイヤーコイルを用いた流動抵抗低減用界面活性剤添加水の直円管内熱伝達促進191198ENHideoInabaNaotoHarukiToruNakataAkihikoHoribeNaoyukiFurumotoKenjiSatoThis paper has dealt with the heat transfer enhancement of flowing water with flow drag reduction additive into a heat transfer tube by inserting wire coils. The non-ion type surfactant was used as the additive to decrease the pipe flow resistance for the heat energy transport system. However, the decrease in the flow resistance was allowed to reduce the heat transfer coefficient in the heat transfer tube. Some kinds of wire coils having different diameters were tried to enhance the heat transfer in the heat transfer tube. The effects of wire coils on the pipe friction and the heat transfer coefficients were elucidated under various experimental parameters of flow velocity, wire coil diameter, pitch and length.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016686692002ゲル状潜熱蓄冷熱体混合水からの空気泡群による直接接触採冷熱221228ENHideoInabaAkihikoHoribeNaotoHarukiMasahiroMurakamiThis paper has dealt with cold heat extraction characteristics from the gel latent-cold-heat storage-material suspension with surfactant to air bubbles. The gel latent-cold-heat storage-material consisted of n-paraffin as the core latent-cold-heat storage-material and water as a heat transfer medium. The relationship between outflow air temperature in latent-cold-heat release process and various parameters was examined experimentally. As a result, especially concentration of the gel latent material added to water exerted an influence on gas holdup and cold heat extraction characteristics to air bubbles. The non-dimensional correlation equations for the temperature effectiveness of latent-heat storage process were derived in terms of the ratio of water layer height to diameter of latent heat material, Reynolds number of air flow, Stefan number and modified Stefan number including air humidity.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016686732002等温冷却壁を有する円管内を流動する潜熱マイクロカプセル混合水の蓄冷熱特性156163ENHideoInabaMyoung-JunKimAkihikoHoribeThe present experiment and numerical analyses have been performed for obtaining the cold heat storage characteristics of a water mixture of microcapsules packed with liquid-solid phase change material (PCM) flowing in a pipe cooled under the constant temperature wall condition. The energy equation was formulated by taking into consideration of the heat release due to the PCM solidification process and the heat transfer enhancement induced by the microconvection of microcapsules. The heat source function in the energy equation was derived from solutions for the solidification in a spherical latent heat material. The governing parameters were found to be latent heat material concentration, cooling wall temperature, microcapsule diameter and velocity of water mixture of the microcapsules. The experimental and numerical results revealed that mean heat transfer coefficient for the water mixture of the latent microcapsules was about 1.6〜2.5 times greater than that for the single phase of water.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016696852003対向垂直加熱・冷却壁を有する矩形密閉容器内の潜熱マイクロカプセルスラリーの熱伝達138145ENHideoInabaKouichiMatsuoAkihikoHoribeThis paper has dealt with the natural convection heat transfer of the microcapsule slurry composed of phase change material (PCM) as a latent heat storage substance. A rectangular cavity with two opposing heating and cooling vertical walls was selected as the present research model. The temperature difference between heating and cooling walls, the width of the cavity and the PCM concentration were set as parameters of natural convection heat transfer. The heat transfer coefficient of heating and cooling wall, the flow velocity profile and the temperature distribution of the microcapsule slurry were calculated by numerical computation. It was clarified that the transportation of latent heat evolved by melting and solidifying of the PCM in the slurry exerted on a strong influence on the natural convection heat transfer. Moreover, it was found that the heat transfer coefficient reached at the local maximal value with an increase in temperature difference between heating and cooling walls. In addition, Nusselt number was influenced by the transportation effect of latent heat that was caused by melting and solidifying of the PCM. The numerical results revealed quantitatively that the natural convection heat transfer depended on the PCM concentration, temperature difference between heating and cooling walls, and width of the rectangular cavity.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016696872003強制対流下における球状吸着剤矩形充填層の側面冷却による吸着促進9097ENHideoInabaJeong-KyunSeoAkihikoHoribeThe present paper has dealt with the one-sidewall cooling effect of spherical adsorbent paticles packed in a rectangular bed on water vapor adsorption characteristics by a 2-dimensional numerical analysis. The analysis model was considered that one-sidewall of a rectangular packed bed with the homogeneous spherical silica-gel particles was cooled and another walls were adiabatic. The moist air flowed into the rectangular packed bed with spherical adsorbent particles. The silica-gel B with high adsorption ability over high relative humidity was selected as a suitable adsorbent. Numerical results revealed the effects of moist air inlet humidity and airflow velocity, size of spherical silica-gel particles and width of the rectangular packed bed and the sidewall cooling terperature on the amount of water vapor adsorption.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016706892004垂直加熱面を有する潜熱マイクロカプセルスラリー充填矩形蓄熱槽の蓄熱特性に関する数値計算209216ENHideoInabaKoichiMatsuoAkihikoHoribeThis paper has dealt with the Heat storage characteristics of the microcapsule slurry composed of phase change material (PCM) as a latent heat storage material and water. A rectangular cavity with a heating vertical wall, which was filled with the microcapsule slurry, was selected as the present research model. The heating wall temperature, the width of the cavity and the PCM concentration were set as parameters. It was clarified that the transportation of latent heat evolved by melting of the PCM in the slurry exerted on a remarkable influence on the natural convection heat transfer. In addition, it was found that the heat transfer coefficient reached a local maximum value with an increase in initial temperature difference between heating wall and PCM. The heat storage completion time also have a local maximum value with an increase in heating wall temperature due to the latent heat by melting the PCM in the slurry.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016706902004減圧下における水蒸気凝結現象を利用した固-液相マイクロカプセルスラリー潜熱蓄熱材の採熱特性444451ENMasatoshiKatayamaHideoInabaAkihikoHoribeNaotoHarukiTsuyoshiManabeRecently, studies have begun on a functional heat transfer medium using fine spherical microcapsules encapsulated with phase-change material and dispersed in water. This enables the medium to maintain fluidity whether the phase-change material is solid or liquid. The present study has clarified the laten-heat storage characteristics of microcapsule slurry by increasing its heat transfer coefficient with the help of evolved heat condensing of vapor from the slurry in heat storage. Paraffin wax with the melting point of 62℃ was encapsulated into the fine microcapsules and used as a phase-change material. The cooling coil surface temperature and concentration of paraffin in the microcapsule slurry were selected as the experimental parameters. As a result, the non-dimensional correlation equations of the heat release completion time and heat transfer coefficient were derived in terms of non-dimensional parameters.No potential conflict of interest relevant to this article was reported.社団法人日本機械学会Acta Medica Okayama0387-5016717022005直円管内を流動する界面活性剤添加有機プラインの流動抵抗と熱伝達挙動573580ENNaotoHarukiHideoInabaAkihikoHoribeShinjiTanakaToruNakataKenjiSatoThe flow drag and heat transfer reduction effects of brine flow with drag reduction surfactants have been investigated from the viewpoint of the effective energy consumption in an industrial cooling system. In this study, Oleyldihy-droxyetyl Amine Oxide (ODEAO) of non-ion surfactant was used as a drag reduction surfactant additive, and Ethylene Glycol (EG) was used as a organic brine. It was found that the viscosity of EG brine with ODEAO had the non-Newtonian behavior. The flow friction coefficient and mean forced convection heat transfer coefficient of the EG brine with ODEAO in a straight pipe were measured for each parameter of concentration of EG, concentration of ODEAO and temperature of the brine with ODEAO. The obtained experimental results indicated that the EG brine with ODEAO exerted an influence on the flow drag and heat transfer reduction.No potential conflict of interest relevant to this article was reported.