Applications of weighted-sum-of-gray-gas model with soot to an experimental aero-engine combustion chamber

Due to the importance of radiation during combustion in the aero-engine, the weighted-sum-of-gray-gas (WSGG) model considering both gas and soot is applied to the combustion modelling for an experimental aero-engine in this work. Five gray gases are chosen to resolve the absorption coefficients of CO2-H2O mixture, with which the Planck-mean absorption coefficients of soot are used for the spectral consideration of gas-soot mixture. Together with the discrete ordinate method, the radiation effects using WSGG model on the combustion are presented. Comparisons are made between full-scale combustion simulations without radiation and those with radiation from gas only or gas-soot mixture. Results show that radiation from either gas or gas-soot mixture leads to no more than 3% differences in temperature and 5% differences in species concentrations. However, the temperature of combustor liner walls in the primary zone (i.e., the main combustion region) is significantly altered with an average of 100 K rise when considering radiation from gas only and a maximum of 500 K rise when considering radiation from gas-soot mixture. Results also show that the temperature of combustor liner walls with radiation from gas-soot mixture becomes more well-distributed than that either without radiation or with radiation from gas only.

Automated summary

This study investigated the effects of radiation on combustion in an experimental aero-engine using the weighted-sum-of-gray-gas (WSGG) model. The results showed that radiation had negligible impacts on temperature and species concentrations, but significantly increased the temperature of the combustor liner walls in the primary zone. Furthermore, radiation from gas-soot mixture led to more uniform temperature distribution compared to radiation from gas only or no radiation.