Abstract
An experimental study to examine the receptivity of a laminar boundary layer to an acoustical disturbance is conducted. The response of the forced oscillations of a Blasius boundary layer over a flat plate model caused by an acoustical disturbance is investigated for frequencies of 70Hz-85Hz. The most important aspect of the present investigation is to determine the behaviour of the disturbance in the boundary layer caused by the receptivity mechanism, and document accurately the acoustical forcing field.
First, the effect of leading edge geometry was examined using two different elliptical profiles. After examined favorable leading edge geometry to the receptivity mechanism, a thin two-dimensional roughness strip is placed across the span of the plate. Such experimental condition provided a receptivity mechanism together with acoustical forcing by a loud-speaker. The measured disturbance profile corresponded to the T-S wave amplitude predicted by linear stability theory. The phase distribution and the wavelength of the disturbance are also in good agreement with predicted values.
