CARS in Aerospace Research

Abstract

Coherent anti-Stokes Raman scattering (CARS) has become one of the indispensable tools of aerospace research. Both in low density gaseous reactive flows and in high pressure combustion, it can return high quality non-intrusive measurements of species densities and temperatures. Certainly, the most common application of CARS in analytical chemistry has been combustion diagnostics. Flames and combustors of all kinds have been investigated. The work was started on small-scale devices [1–3], but soon large scale industrial furnaces [4], piston engines [5, 6], jet engine combustors [7–9] and supersonic combustors [10] were studied. Variants of the technique, like simultaneous multiple species detection, have been proposed and tested [11–13]. At the same time, attention was drawn to several weaknesses of CARS, like saturation [14–17] and lack of spatial resolution [18], which may cause substantial errors and are frequently not given enough attention. Roughly speaking, however, application to combustion has matured, and a substantial fraction of the technical research on CARS now centers on refining lineshape reduction at high pressures [19–23] and on the application of resonance-enhanced CARS to detection of radicals at high pressures [24].KeywordsEquivalence RatioProbe VolumeRotational TemperatureAerospace ResearchRotational DistributionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.