start-ver=1.4
cd-journal=joma
no-vol=408
cd-vols=
no-issue=
article-no=
start-page=117978
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=202610
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=A flexible PVDF-based galloping flow sensor
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Effective monitoring of low flow velocities in small rivers and irrigation channels is hindered by the power requirements and maintenance costs of existing technologies. This study proposes a novel flexible piezoelectric polymer flow sensor utilizing galloping vibration to detect flow velocity in the low range (?  0.1?m/s). The sensor features a flexible cantilever structure composed of a silicone rubber beam embedded with a polyvinylidene fluoride (PVDF) film and a tip pillar. Unlike conventional devices based on flow-induced vibration, the use of low-stiffness materials enables the induction of self-excited vibration even under weak fluid forces. Computational fluid dynamics (CFD) analysis has been conducted to optimize the tip shape; a D-shaped semicylinder is selected over a cylinder and a square prism because the geometry maximizes the lift force per unit mass, ensuring efficient energy conversion. To predict sensor behavior, a coupled mechanical-fluid-electrical model was developed. Specifically, the model accounts for the static deflection angle caused by fluid drag. Water channel experiments demonstrated that sensors with beam thicknesses under 4?mm successfully generated stable periodic outputs at 0.1?m/s, a regime previously difficult for galloping-based devices. Conversely, thicker beam which has a thickness of 8?mm achieved higher outputs at higher velocities but failed to actuate at low speeds. Furthermore, the study showed a vibration suppression phenomenon in flexible beams at high flow velocities due to excessive static deflection, which was accurately reproduced by the analytical model. These findings establish structural stiffness as the critical design parameter for optimizing the operable velocity range of flow sensors.
en-copyright=
kn-copyright=

en-aut-name=KuroseMitsuki
en-aut-sei=Kurose
en-aut-mei=Mitsuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=KandaTakefumi
en-aut-sei=Kanda
en-aut-mei=Takefumi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=SatoYuya
en-aut-sei=Sato
en-aut-mei=Yuya
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=WakimotoShuichi
en-aut-sei=Wakimoto
en-aut-mei=Shuichi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=YamaguchiDaisuke
en-aut-sei=Yamaguchi
en-aut-mei=Daisuke
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

en-aut-name=HiejimaShinji
en-aut-sei=Hiejima
en-aut-mei=Shinji
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=6
ORCID=

en-aut-name=UedaTakeji
en-aut-sei=Ueda
en-aut-mei=Takeji
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=7
ORCID=

affil-num=1
en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=

affil-num=2
en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=

affil-num=3
en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=

affil-num=4
en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=

affil-num=5
en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=

affil-num=6
en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University
kn-affil=

affil-num=7
en-affil=Hydro-VENUS Co., Ltd., Okayama University
kn-affil=
en-keyword=Flow velocity sensor
kn-keyword=Flow velocity sensor
en-keyword=Piezoelectric polymer
kn-keyword=Piezoelectric polymer
en-keyword=Flow induced vibration
kn-keyword=Flow induced vibration
en-keyword=Galloping vibration
kn-keyword=Galloping vibration
END

start-ver=1.4
cd-journal=joma
no-vol=33
cd-vols=
no-issue=
article-no=
start-page=69
end-page=69
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2012
dt-pub=201202
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=編集後記
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=

en-aut-name=
en-aut-sei=
en-aut-mei=
kn-aut-name=比江島慎二
kn-aut-sei=比江島
kn-aut-mei=慎二
aut-affil-num=1
ORCID=

affil-num=1
en-affil=
kn-affil=岡山大学環境管理センター
END