CO2 Spontaneous Raman Scattering: an alternative thermometry for turbulent reactive flows

Economic and ecological issues make necessary an in-depth study of combustion processes. Whether in-situ measurements of temperature are a key point to validate numerical combustion model, yet they still challenging in high temperature reactive flows. Previous studies have shown that non-intrusive thermometry method based on spectral fitting of N 2 Spontaneous Raman Scattering (SRS) was relevant to precisely characterize turbulent air flames. However, this technique may be less appropriate to study emerging processes such as oxyfuel combustion. The purpose of this paper is to demonstrate that spectral fitting of CO 2 SRS is a compelling alternative for temperature measurements in oxyfuel flames where N 2 is absent. Using a pure vibrational description of CO 2 SRS spectra, spectral fitting temperature measurements are made in several cases (heated gases, premixed laminar CH4/air Bunsen flames) to assess the accuracy over a wide range of temperature, from 300 K to 2200 K. Measurements uncertainties depending on experimental conditions and CO 2 signal levels are also discussed. Finally, single-shot temperature profiles in the flame front of a premixed CH 4 /O 2 /CO 2 Bunsen flame shows an excellent agreement with simulation. This study opens a lot of prospects for future experimental studies of turbulent oxyfuel flames, especially in the objective of carbon capture and storage.