Inversion of combustion gas temperature/concentration profile with radiation/turbulence interaction using SRS

The spectral remote sensing (SRS) method is applied to the combustion gas with radiation/turbulence interaction to invert the temperature and concentration profiles. The flame is made and controlled to be optically thin per each fluctuation length so that spatially fluctuating gas layer can be treated equivalently as timewisely fluctuating one sharing identical expression in the radiative transfer equation. Then, the spectral intensity, temperature and concentration distributions are measured for the inversion and as the reference solutions. From the inversion results, we find that SRS can successfully invert the coupled temperature/concentration fluctuation amplitudes and mean values. For the two cases of experiment, inverted values are in good agreement with measured ones. However, SRS cannot find the detailed local fluctuation parameter such as pattern or phase, etc. as far as they do not affect the resulting radiative intensity. So, it is deduced that the pattern or phase is not so influential, whereas the mean value and the fluctuation amplitude of temperature/concentration profile are important parameters for the radiative intensity in the case of the optically thin condition. Further, the radiation/turbulence interaction is verified to play an important role in the radiation.