This paper presents a wall modeling study of turbulent reacting flows of CH₄/O₂ mixtures towards accurately predicting the wall heat flux in combustion chambers. The study focuses on the description of flow and chemistry within inner layers and compares the accuracy of wall functions and ordinary differential equation (ODE) based wall models assuming equilibrium and frozen chemistry. Two test cases of turbulent reacting channel flow and GCH₄/GOX rocket combustion demonstrate that the ODE-based frozen wall model is more accurate than other models in predicting wall shear stress and heat flux. The mixture composition within the inner layer is reproduced accurately by assuming the chemical frozen state, but assuming chemical equilibrium leads to overestimated changes in the mixture composition. The investigation of the effects of wall temperature shows that the wall function models significantly overestimate the wall shear stress and heat flux with decreasing wall temperature while the accuracy of the ODE-based frozen wall model is not affected by the wall temperature. The ODE-based frozen wall model derived from the proper description of the chemical state and thermodynamic properties of the gas mixture allow to accurately and robustly predict the wall heat flux in reacting flows, while the chemical frozen assumption maintains model simplicity.

本文对CH ₄ / O ₂混合物的湍流反应流进行壁建模研究，以准确预测燃烧室中的壁热通量。该研究着重描述内层的流动和化学性质，并比较了假设平衡和冻结化学性质的壁函数和基于常微分方程（ODE）的壁模型的准确性。湍流反应通道流和GCH _4的两个测试案例/ GOX火箭燃烧表明，基于ODE的冻结壁模型在预测壁切应力和热通量方面比其他模型更准确。通过假定化学冻结状态可以准确地复制内层内的混合物成分，但是假设化学平衡会导致混合物成分的变化被高估。对壁温度影响的研究表明，壁函数模型会随着壁温度的降低而高估壁剪切应力和热通量，而基于ODE的冻壁模型的精度不受壁温度的影响。基于ODE的冻结壁模型源自对气体混合物的化学状态和热力学性质的正确描述，可以准确而可靠地预测反应流中的壁热通量，