绕翼型低雷诺数流动的数值仿真

摘要

层流转捩到湍流及翼型表面分离泡的产生是绕翼型低雷诺数流动的重要特征,对流场产生很大影响.针对这一流动现象,选取E387翼型为研究对象,采用求解雷诺平均N-S方程的有限体积法,结合当前应用较广泛的Spalart-Allmaras、SST k-ω、Realizable k-ε三种湍流模型,对雷诺数为3×105时翼型绕流流场进行了数值模拟；并将结果与Selig等人的风洞实验数据进行对比,评估三种湍流模型对绕翼型低雷诺数流动的模拟能力.基于对翼型阻力计算不准原因的分析,提出了一种基于Michel转捩判据的数值模拟方法,分别从分离泡的模拟、壁面摩阻分布、翼型阻力系数等方面与实验数据进行对比.结果表明该方法可以较好地模拟低雷诺翼型绕流流场.%Laminar-turbulent transition and the separation bubble are the typical characteristic of the low-Reynolds-number flow over airfoils.They have the significant impact on the overall flow field.Numerical simulation of the flow over E387 airfoil are performed using the RANS model by solving the Navier-Stokes equations with three turbulence model operating at a Reynolds number 3 × 105.The ability in numerical simulation of the Spalart-Allmaras model,the SST k-ω model and the Realizable k-ε model are evaluated by comparing the results with the Selig's experiment data.A novel simulation approach of fixing the transition point is built and validated in the skin friction coefficient distribution,the drag coefficient of airfoil and the separation bubble simulation.The results show good agreement with experiment data.