Large eddy simulation assessment of an advanced perforated wall model for effusion cooling of gas turbine combustor

To accurately predict the effusion cooling process of a gas turbine combustor liner, a simplified heat and mass transfer model named the Advanced Perforated Wall Model (A-PWM) is developed, and turbulent flow and vortex dynamics are investigated using large eddy simulation (LES). The model is first validated for effusion cooling with a single cylindrical hole, and the prediction results match those of the conjugate heat transfer (CHT) model and experimental data. Due to the simplification of the physical cooling hole geometry, the LES-A-PWM reduces grid usage by 73% and improves computational efficiency by 62.55% compared to LES-CHT. It is also found that the local cooling effectiveness of LES-A-PWM shows deviations compared to experimental data, and LES-CHT results at the cooling hole outlet. Further analysis shows counter-rotating vortex pairs (CRVPs) form at the cooling hole outlet, enhancing mixing between cooling and hot flows and increasing Reynolds stress, thus affecting effusion cooling effectiveness. However, unlike resolved LES-CHT, the LES-A-PWM neglects the hole geometry and applies a uniform velocity, causing slight deviations near the outlet. Later, simulations on a combustor liner with 20 holes show that A-PWM agrees well with CHT and experimental data, maintaining deviations within 10%. The required mesh cells and computation time by LES-A-PWM are reduced by 35.8% and 35.9%, respectively. As the number of holes increases, turbulence interactions intensify between adjacent holes, while local heat transfer around the cooling jets weakens. These results demonstrate that A-PWM, assessed through LES, provides an accurate and efficient approach for design-level evaluation of combustor liner cooling.