start-ver=1.4 cd-journal=joma no-vol=64 cd-vols= no-issue=4 article-no= start-page=244 end-page=252 dt-received= dt-revised= dt-accepted= dt-pub-year=2016 dt-pub=20160805 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=Effects of Upstream Disturbances on Supersonic Flowfield with Transverse Injection kn-title=’ī‰đ‘Ž•Į–Ę•ŽŽË—Ž‚ęę‚֏㗎ï—‚Š‹y‚Ú‚·‰e‹ŋ en-subtitle= kn-subtitle= en-abstract= kn-abstract= Effects of upstream disturbances on a transverse jet into Mach 2 supersonic flow were investigated by using single-time two-point spatial correlations of fluctuating velocities in the flowfield. The fluctuating velocity was measured by stereoscopic PIV. We categorized the upstream disturbances into two factors: incoming boundary layer on the injection port and weak oblique shock wave impinging ahead of the injection port. The velocity fluctuations in the upstream boundary layer had a long positive correlation region in the boundary layer. This is the evidence that very large-scale motion (VLSM) existed in the boundary layer developed on our test section. The correlation region bifurcated into the regions along the bow shock wave and the outer jet boundary. The correlation length was 10-hold longer than the boundary layer thickness. Fluctuation of the weak shock wave was induced by VLSM developed on the opposite wall to the injection wall. The velocity fluctuation due to the weak shock wave also had a long positive correlation region along the oblique shock wave. However, it had no correlation with the jet. en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=‰Í“ārŒ› kn-aut-sei=‰Í“ā kn-aut-mei=rŒ› aut-affil-num=1 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=‰Y–{ãĕ― kn-aut-sei=‰Y–{ kn-aut-mei=ãĕ― aut-affil-num=2 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=Ą’JŒÜ˜Y kn-aut-sei=Ą’J kn-aut-mei=ŒÜ˜Y aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=‰ŠŽR‘åŠw‘åŠw‰@ŽĐ‘R‰ČŠwŒĪ‹†‰Č affil-num=2 en-affil= kn-affil=“Œ–k‘åŠw‘åŠw‰@HŠwŒĪ‹†‰Č affil-num=3 en-affil= kn-affil=“Œ–k‘åŠw‘åŠw‰@HŠwŒĪ‹†‰Č en-keyword=Scramjet Combustor kn-keyword=Scramjet Combustor en-keyword=Wall Injection kn-keyword=Wall Injection en-keyword=Spatial Correlation kn-keyword=Spatial Correlation en-keyword=Turbulence kn-keyword=Turbulence en-keyword=Very Large Scale Motion kn-keyword=Very Large Scale Motion en-keyword=Stereoscopic PIV kn-keyword=Stereoscopic PIV END start-ver=1.4 cd-journal=joma no-vol=63 cd-vols= no-issue=4 article-no= start-page=166 end-page=174 dt-received= dt-revised= dt-accepted= dt-pub-year=2015 dt-pub=20150728 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=Fast-framing Focusing Schlieren Visualization of Two-dimensional Wing Buffet kn-title=‚‘Ž’f‘wƒVƒ…ƒŠ[ƒŒƒ“‚É‚æ‚é“ņŽŸŒģ—ƒƒoƒtƒFƒbƒg‚Ė‰ÂŽ‹‰ŧ en-subtitle= kn-subtitle= en-abstract= kn-abstract= We visualized two-dimensional wing buffet using fast-framing focusing schlieren method. A supercritical airfoil of NASA SC(2)-0518 was used in this study. Mach number of the freestream was 0.7, and Reynolds number based on the wing code (c) was 5~106. Angle of attack without corrections (ƒŋ) was changed from 4‹ to 6‹. The present focusing schlieren system had }18mm depth of field, which was narrow than spanwise region where the two-dimensionality of the flow field was maintained. 8,345 successive images were captured by high speed CMOS camera with 7,000 frames per second with 20ƒĘs exposure time. The present imaging system well captured the shock wave motion on the airfoil. At ƒŋ = 4‹, the shock wave was positioned at x/c?0.45. The shock wave was slightly fluctuated with a frequency of 585.5Hz. Above ƒŋ = 5‹, the wing buffet occurred. The buffet frequency increased as increasing ƒŋ. The focusing schlieren movies revealed that the shock wave was bifurcated on the wing surface, as the shock traveling upstream. The boundary layer largely separated from the leading oblique foot of the bifurcated shock wave, whereas, the bifurcated shock wave changed into a normal shock and the flow separation disappeared, as the shock traveling downstream. For both cases, many pressure waves propagated from the downstream of the shock wave to the upstream. These waves merged with the shock wave, and seem to drive the shock oscillation. en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=‰Í“ārŒ› kn-aut-sei=‰Í“ā kn-aut-mei=rŒ› aut-affil-num=1 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=ŽRŒû^ŒÞ kn-aut-sei=ŽRŒû kn-aut-mei=^ŒÞ aut-affil-num=2 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=Ž’rr•ã kn-aut-sei=Ž’r kn-aut-mei=r•ã aut-affil-num=3 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=’†“‡“w kn-aut-sei=’†“‡ kn-aut-mei=“w aut-affil-num=4 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=ē“Ą‰q kn-aut-sei=ē“Ą kn-aut-mei=‰q aut-affil-num=5 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=_“cG kn-aut-sei=_“c kn-aut-mei=G aut-affil-num=6 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=–öĢáÁˆę˜Y kn-aut-sei=–öĢ kn-aut-mei=áÁˆę˜Y aut-affil-num=7 ORCID= affil-num=1 en-affil= kn-affil=‰ŠŽR‘åŠw‘åŠw‰@ŽĐ‘R‰ČŠwŒĪ‹†‰Č affil-num=2 en-affil= kn-affil=‰ŠŽR‘åŠw‘åŠw‰@ŽĐ‘R‰ČŠwŒĪ‹†‰Č affil-num=3 en-affil= kn-affil=‰F’ˆq‹óŒĪ‹†ŠJ”­‹@\ affil-num=4 en-affil= kn-affil=‰F’ˆq‹óŒĪ‹†ŠJ”­‹@\ affil-num=5 en-affil= kn-affil=‰F’ˆq‹óŒĪ‹†ŠJ”­‹@\ affil-num=6 en-affil= kn-affil=‰F’ˆq‹óŒĪ‹†ŠJ”­‹@\ affil-num=7 en-affil= kn-affil=‰ŠŽR‘åŠw‘åŠw‰@ŽĐ‘R‰ČŠwŒĪ‹†‰Č en-keyword=Flow Visualization kn-keyword=Flow Visualization en-keyword=Shock-boundary Layer Interaction kn-keyword=Shock-boundary Layer Interaction en-keyword=Supercritical Airfoil kn-keyword=Supercritical Airfoil en-keyword=Two-dimensional Transonic Wind tunnel kn-keyword=Two-dimensional Transonic Wind tunnel END