ID 56129
Title Alternative
Fast-framing Focusing Schlieren Visualization of Two-dimensional Wing Buffet
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Author
河内 俊憲
山口 真伍
小池 俊輔
中島 努
佐藤 衛
神田 宏
柳瀬 眞一郎
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 (α) 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 20μs exposure time. The present imaging system well captured the shock wave motion on the airfoil. At α = 4°, the shock wave was positioned at x/c∼0.45. The shock wave was slightly fluctuated with a frequency of 585.5Hz. Above α = 5°, the wing buffet occurred. The buffet frequency increased as increasing α. 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.
Keywords
Flow Visualization
Shock-boundary Layer Interaction
Supercritical Airfoil
Two-dimensional Transonic Wind tunnel
Published Date
2015-07-28
Publication Title
日本航空宇宙学会論文集
Volume
volume63
Issue
issue4
Publisher
日本航空宇宙学会
Start Page
166
End Page
174
ISSN
13446460
NCID
AA11307372
Content Type
Journal Article
language
日本語
OAI-PMH Set
岡山大学
File Version
publisher
DOI
Related Url
isVersionOf https://doi.org/10.2322/jjsass.63.166