Receptivity of a shear layer separating at a convex corner in the wall is e
xamined experimentally. Acoustic forcing is applied to excite instability w
aves. Particular attention is focused on the comparison of receptivity coef
ficient between a sharp-edged corner and a rounded corner whose radius of c
urvature is 20 times the boundary-layer displacement thickness. The results
clearly show that the receptivity coefficient is quite sensitive to the sh
arpness of the corner and that the amplitude of the excited instability wav
e is twice larger for the sharp corner compared with the rounded corner. Th
e same dependency of the receptivity coefficient on the corner sharpness is
verified by analyzing the shear layer response to wind-tunnel background n
oise without acoustic forcing. (C) 2000 The Japan Society of Fluid Mechanic
s and Elsevier Science B.V. All rights reserved.