Trasonic Cascade Wind Tunnel Modification and Initial Tests.

The transonic cascade wind tunnel at the Turbomachinery Laboratory was modified by incorporting a perforated wall section in the upper nozzle block. The purpose of this modification was to cancel the oblique shock waves from the cascade blades and to aid in starting the supersonic flow in the tunnel. Tests results indicated that the modification performed successfully. Supersonic flow was established through the cascade blading which models the relative flow at the tip of the laboratorys transonic compressor. A butterfly valve must yet be installed in the cascade exhaust to produce back pressures corresponding to the compressors transonic operation. Author