Boundary Layer Development on Perforated Walls in Transonic Wind Tunnels

摘要

The boundary layer development on the perforated walls of a transonic wind tunnel was studied experimentally. The measurements were made under real model testing conditions to provide a better understanding of the flow, so that a proper boundary condition for wall interference calculations could be formulated. The experimental results show that the boundary layer displacement effect is minimal for the lower wall but for the upper wall the normal velocity induced can be about three times greater than that at the wall. The wall characteristics are strongly modulated by the growth rate of the boundary layer. It also shows that the linear boundary condition used in the wall interference calculations does not adequately reproduce the nonlinear development of the flow at the wall.