Hydrogen Chirped-Probe-Pulse Femtosecond Coherent anti-Stokes Raman Scattering Thermometry in a High-Pressure GH 2 /GO 2 Model Rocket Combustor

This study presents temperature measurements inside a gH2/gO2 single-element model rocket combustor using H2 chirped-probe-pulse coherent anti-Stokes Raman scattering (CPP fs CARS) thermometry. The model rocket combustor features large optical access at all four sides of the chamber, which enables spatially resolved temperature measurements over large radial distances from the injector axis. The rocket combustor operates at a mean chamber pressure of 1 MPa with an O/F ratio of 3.0. Single-shot H2 CARS spectra were collected at 5 kHz and agreed well with the theoretical model. The probe volume was scanned along the vertical axis at 44.45 mm downstream of the injector at various radial locations. The results show asymmetrical temperature distribution along the vertical axis of the combustor, with a peak temperature near 2500 K at the positive side of the axis. This observation is further confirmed by high-speed chemiluminescence images taken at 70 kHz. Overall, these results provide quantitative data to support the validation of numerical models and enhance the understanding of combustion dynamics in gas-gas rocket combustor.