Experiments to Assess the Influence of Changes in the Tunnel Wall Boundary Layer on Transonic Wall Crossflow Characteristics.

摘要

The equivalent porosity of the test section wall in a transonic wind tunnel with a fixed geometric porosity and varying wall boundary-layer displacement thickness, has been investigated. Previous experiments have demonstrated that the boundary-layer displacement thickness on the wall influences the wall crossflow characteristic. Experimental data from a Ludwieg tube type of transonic tunnel are compared with data from conventional transonic tunnels in the Mach number range from 0.95 to 1.15. The displacement thickness studied is comparatively thin and represents typical values which will be encountered in future high Reynolds number transonic tunnels.