Spectral effects of radiating gases and soot on an experimental aero-engine combustion chamber using full-spectrum k-distribution method

Abstract

Radiative heat transfer is the main mode of heat transfer and has been proven to be important in the aero-engine combustion. Those radiating gases and soot resulted from combustion may display very strong spectral, or “nongray” behavior, which is difficult to both characterize and evaluate. In this work, the full-spectrum k-distribution (FSK) method is employed to resolve the spectral behavior of both radiating gases and soot during combustion in an experimental aero-engine. Different FSK-based spectral treatments are combined to illustrate how the spectral behavior affects the aero-engine combustion. Those weighted-sum-of-gray-gases (WSGG) results previously done by the authors (Wang, et al. 2024) are also partially compared to the FSK results in this work. Results show that different FSK-based spectral treatments result in small differences for temperature distribution of the flow field. However, since different spectral models are found to impose a considerable effect on radiative heat transfer rate, it is inferred that spectral behavior may be deeply coupled with the generation of pollutants. Results also show that the wall temperature of the combustor liner is highly affected by the spectral model: ignoration of soot radiation underestimates the wall temperature while assuming soot to be gray overestimates the wall temperature. Therefore, high-fidelity spectral models are recommended during the modelling of aero-engine combustion.