Coherent Anti-Stokes Raman Scattering Temperature Measurements on an Air-Breathing Ramjet Model

Coherent anti-Stokes Raman scattering was used to measure nitrogen single-pulse spectra at the entrance and exit area of a thrust nozzle. Thermodynamic nonequilibrium effects were proved at the exit of the hypersonic nozzle, belonging to an air-breathing, hydrogen-combusting ramjet model. To determine the accurracy of extracted rotational and vibrational temperatures, additional laboratory experiments were performed. The nozzle expansion was characterized by wall pressure measurements