Chirped-Probe-Pulse Femtosecond CARS H₂ Thermometry in a High-Pressure Model Rocket Combustor

Abstract

View Video Presentation: https://doi.org/10.2514/6.2023-1931.vid Chirp-probe-pulse femtosecond CARS (CPP fs CARS) temperature measurements of H2 molecules inside a single-element model gH2/gO2 rocket combustor are presented. Measurements were performed at O/F 3.0 up to a mean chamber pressure of 7 MPa along the central axis of the combustion chamber. Strong chemiluminescence is successfully avoided by spectral filtering and careful choice of pump and probe frequencies. Single-shot spectra were collected with high signal-to-noise ratio (SNR) at 5 kHz. Experimental spectra agree well with theoretical spectra, which are generated from a phenomenological model. This is, to our knowledge, the first demonstration of fs CARS measurements inside a high-pressure rocket combustor. These results highlight the potential of using H2 CPP fs CARS thermometry to provide quantitative data in high-pressure experiments for the study of combustion dynamics and model validation efforts at application relevant operating conditions.