Numerical Investigation of Fuel-Rich Gas Properties Effects on Film Cooling Performances

This study clarifies the impact of fuel-rich gas properties on film cooling performances by proposing a gas model with changing properties considering chemical equilibrium. This model is compared against reference gas models with constant properties and varying thermal conductivities. The comparisons reveal the effects of specific heat capacity and thermal conductivity on the distribution of temperature and heat flux through applying Reynolds-Averaged Navier-Stokes equations. Calculations of gas properties indicate that the mixing of fuel-rich gas and coolant can result in the reduction of specific heat capacity and thermal conductivity. Therefore, the gas model with changing properties can predict an elevated average near-wall temperature and decreased wall heat flux against gas models with constant properties. The maximum prediction deviations can reach up to 2.557% and 24.995%, respectively. Additionally, changing properties can weaken the counter rotating vortex pair due to reduced jet-crossflow shearing, diminished coolant dissipation, and enhanced film coverage. © 2024 Science Press. All rights reserved.