TY - JOUR
T1 - Effect of micron-sized roughness and sound receptivity on a swept wing boundary-layer transition
AU - Kohama, Yasuaki
AU - Watanabe, Hajime
PY - 1996
Y1 - 1996
N2 - The effect of micron-sized roughness in the leading edge region on a swept wing boundary-layer transition is examined experimentally in detail. By applying sound waves from a loud speaker, sound receptivity to turbulent transition is also investigated. Results showed that such a minute roughness element (k=45 μm in height, 1 mm in diameter, k/δ=0.23) placed at x=40 mm resulted in early transition. In the case that no transition enhancement was observed in the presence of a single roughness element, early transition also occurred with sound excitation. Low frequency disturbance f1 responded strongly to the sound frequency, in particular, to the direction of the sound waves. Critical spacing of roughness elements where the transition is amplified the most seems to exist in the range of λ/δ = 1.3. It is also noted that no enhancement of transition occurs when the roughness element is placed beyond 20% of the chord length.
AB - The effect of micron-sized roughness in the leading edge region on a swept wing boundary-layer transition is examined experimentally in detail. By applying sound waves from a loud speaker, sound receptivity to turbulent transition is also investigated. Results showed that such a minute roughness element (k=45 μm in height, 1 mm in diameter, k/δ=0.23) placed at x=40 mm resulted in early transition. In the case that no transition enhancement was observed in the presence of a single roughness element, early transition also occurred with sound excitation. Low frequency disturbance f1 responded strongly to the sound frequency, in particular, to the direction of the sound waves. Critical spacing of roughness elements where the transition is amplified the most seems to exist in the range of λ/δ = 1.3. It is also noted that no enhancement of transition occurs when the roughness element is placed beyond 20% of the chord length.
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U2 - 10.1299/kikaib.62.2269
DO - 10.1299/kikaib.62.2269
M3 - Article
AN - SCOPUS:0030168768
VL - 62
SP - 2269
EP - 2276
JO - Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
JF - Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
SN - 0387-5016
IS - 598
ER -