Chapter 4.5 - Shock Tubes and Tunnels: Facilities, Instrumentation, and Techniques

Abstract

This chapter provides an overview of supersonic and hypersonic wind tunnels. Wind tunnels are used for simulating aerospace systems flight conditions in the laboratory. In principle, these facilities include a gas supplying system (source), a nozzle that transforms the gas from reservoir conditions to test conditions, the test section, and finally a diffuser and an exhaust system. Supersonic and hypersonic wind tunnels of various types are currently used in research laboratories and in aerospace related industries. These facilities work on the basis of the classical gas dynamic theory. The wind tunnels test cross-section sizes that can vary from a few centimeters up to an order of magnitude of a meter. Wind tunnel types differ by some of their operating aspects. Continuous operating wind tunnels offer long duration flow but need a high power supply in high-density flow cases. In general, low-density flow facilities are of continuous type. On the other hand, blow-down wind tunnels are characterized by short running time but can produce high Mach number and high-enthalpy flows. Blow-down wind tunnels are the most used facilities, with wind tunnels equipped with specific instrumentation depending on their flow regimes.