Assessment of radiative heat transfer with/without turbulence-radiation interaction in aero-engine swirling combustors of different geometric scales

Radiative heat transfer (RHT) and Turbulence-Radiation Interaction (TRI) are closed related with the internal temperature, NO formation and liner temperature of aero-engine combustors. In this work, four cases with different geometric scales are constructed to investigate the effect of RHT with/without TRI on flames within swirling combustors, where the Damkohler number is kept constant to preserve similarity of flames. The results show that, for the prototype DLR combustor, RHT without TRI greatly decreases the internal temperature, especially for the central recirculation zone, which leads to a decrease in outlet temperature by 97.0 K and a reduction in NO emission by 40.6 %. TRI enhances radiative heat loss by 27.7 %, which further decreases the outlet temperature by 27.6 K and NO emissions by 20.6 %, and increases the wall radiative heat flux by 21.7 %. As the geometric scale increases, the impacts of RHT with/without TRI on swirling flames decreases. Specifically, as the geometric scale is enlarged by 6 times, radiative heat loss caused by RHT without TRI reduces from 5.7 % to 4.2 %, while that by RHT with TRI decreases from 7.3 % to 4.8 %, which further affects the temperature, NO emission and wall radiative heat flux.