Practical Aspects of Cascade Wind Tunnel Research

Abstract

This paper deals mainly with the development of a high-speed wind tunnel for the testing of turbine or compressor blade cascades under two-dimensional air flow at velocities up to that of sound. It includes a brief résumé of the early history of the technique, and goes on to enumerate the variables which must be brought under the operator's control. Reference is made to methods of presentation of results, including the use of optical systems for demonstration of shock phenomena. Finally, the control system evolved for operating the high-speed tunnel is described, and some notes are added on the protection of the operators from fatigue induced by monotony and noise.