Tunable Diode Laser Absorption Spectroscopy as a Flow Diagnostic Tool: A Review

Abstract

Optical diagnostic techniques are routinely being used in highspeed fl ow facilities to measure fl ow properties such as concentration,temperature and velocity, and thus, to study the fl ow physics. One suchtechnique, tunable diode laser absorption spectroscopy (TDLAS), hasproved to be particularly suitable for hostile environments such as shocktunnels and fl ight tests. The fundamentals, operating principle, applicationsand scope of the technique in high speed fl ow research is discussed inthis review, with references to some relevant examples.