Collected Works of H. S. Tsien (1938-1956)

Wind-Tunnel Testing Problems in Superaerodynamics

Hsue-shen Tsien*

(Massachusetts Institute of Technology)

Summary

The problems in the experimentation of rarefied gas are discussed. First, the extremely large viscous effects in a wind-tunnel nozzle are shown. Then the difficulties of flow measurement are surveyed, pointing out particularly the unconventional behavior of the Pitot tube in rarefied gas. The performance of a hot-wire anemometer is then studied in some detail to show its feasibility. Finally, the rules for achieving complete flow similarity of rarefied gas flow are formulated.

Introduction

Wind tunnels are, perhaps, the most useful tool in aerodynamic investigations and certainly have contributed much in the modern development ...