Download or read book Boundary Layer Receptivity Theory written by and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Receptivity processes by which free-stream disturbances generate Tollmien-Schlichting waves in boundary layers have been analyzed using asymptotic methods for high Reynolds numbers. Vortical and acoustic free-stream disturbances have been considered. Receptivity occurs in the vicinity of the leading edge, and in localized regions further downstream where some feature (e. g., a wall hump) produces a short-scale disturbance to the mean flow. Nonlinear effects related to the free-stream pressure field have been found to play an important role in localized receptivity to vortical disturbances. For leading- edge receptivity, the influences of the body nose radius and aerodynamic loading in the leading-edge region have been analyzed. In the absence of aerodynamic loading, an increase in the body nose radius decreases the leading-edge receptivity coefficient. However, strong aerodynamic loading leads to a dramatic increase in the leading-edge receptivity coefficient, negating the decrease due to a larger nose radius. The propagation of an instability wave past a junction between a rigid wall and a surface with non-zero compliance or admittance has also been analyzed. The junction can cause energy to be scattered from the instability wave to higher eigenmodes, effectively attenuating the instability wave.