一种积分形式的湍流边界层壁面热流预测方法

An integral method for estimating wall heat flux in spatially developing turbulent boundary layers

本文基于雷诺平均能量方程提出了一种积分形式的湍流边界层壁面热流预测方法,该方法仅需要提供一个流向位置处的平均温度和法向热流密度剖面.此外,采用本方法预测壁面热流只需要远离壁面区域的平均流场分布,而不需要整个边界层内的流场数据.通过研究积分上下限对壁面热流预测模型精度的影响,发现积分上限和积分下限对模型相对误差的影响较小.经文献中大量的直接数值模拟和实验测量数据验证,该方法的相对误差在±4%以内.本文提出的壁面热流预测模型适用于不可压缩零压力梯度湍流边界层,具有精度高、鲁棒性强等优点.

A novel method based on an integral analysis of the Reynolds-averaged energy equation is proposed to determine the wall heat flux in a spatially developing turbulent boundary layer.The method requires the wall-normal profiles of the mean temperature and wall-normal heat flux at only one streamwise location.Moreover,only the mean profiles in the region far away from the wall are required for estimation of the wall heat flux,instead of the data within the whole boundary layer.The influences of integration limits on the accuracy of the method are investigated,showing that the lower and upper integration limits have insignificant effects on the relative error.A number of direct numerical simulation and experimental datasets available in the literature are employed to assess the accuracy of the present method over a wide range of Reynolds numbers.The wall heat flux determined using the proposed method is found to be within±4%in agreement with the published values.The predictive model is shown to be robust and accurate in incompressible turbulent boundary layers under zero pressure gradient.