【作者】 肖梦娟； 李师尧； 佘振苏；

【Author】 Xiao Mengjuan;Li Shiyao;She Zhensu;College of Engineering,Pek ing University;

【机构】 北京大学工学院；

【摘要】 我们报告一个新型代数湍流模型——SED-SL模型,其实现了对于平板转捩流动以及翼型流动的精确预测。SED-SL模型基于结构系综理论(SED理论)对壁湍流中应力长函数沿壁面法向发展的多层结构解析表达,并引入其特征参数沿流向的多层结构形式来刻画层流到湍流的转捩过程,是首次基于湍流边界层的理论所提出的工程湍流模型。首先针对不同来流条件下的平板转捩流动,该模型给出与实验以及DNS测量一致的摩阻。进一步,对翼型升阻力系数的预测结果与实验测量值的比较表明,在对实验所报告的来流条件进行合理修正的情况下,在整个马赫数和攻角变化范围内,SED-SL模型计算结果与实验精确相符(升力的偏差控制在2%以内,阻力系数的偏差对于RAE2822翼型流动以及NACA0012翼型流动分别控制在2Counts以及6Counts左右),偏差逼近到了实验的测量精度极限。相比之下,BL以及SA模型所得到的阻力系数过大,远远大于SED-SL模型。此次应用最显著的成果在于模型参数都具有对应的物理意义,使得我们能够成功地从实验和计算的经验数据中提取出物理信息,为提出广泛有效的工程转捩模型奠定了良好的基础。更多还原

【Abstract】 We report a new algebraic transition model based on a newly developed symmetry-based approach to quantifying wall turbulence.The model specifies a multi-layer profile of a stress length function in both the streamwise and normal direction to the wall,which thus define the eddy viscosity in the Reynolds averaged Navier-Stokes equation(e.g.zero-equation model).With a calibration using compressible flat plate simulation data at Mach number 2.25,the model yields excellent prediction of the streamwise development of friction coefficient with varying incoming turbulence intensities/scales and varying Mach numbers,comparing to both experimental(T3 series) and simulation data of transitional flows.With further applying this model to the flow over airfoil,significantly improved result has been obtained(with marginally adjusted Mach number and angle of attack compared to the freestream condition configuration of available experiments) that is much satisfied than the computations using other turbulence models.For all the cases of two investigated airfoils,RAE2822 transonic airfoil and NACA0012 airfoil,the deviation of CL between computations and experiments is almost bounded within 2%,and the deviation of CD is approximately bounded within 2 counts for RAE2822 and 6 counts for NACA0012 respectively.The most remarkable outcome is the physical interpretation of the model parameters: they specify the corresponding multi-layer structure of turbulent boundary layer,enabling one to extract physical information from fitting experimental and simulation data,so as to reproduce the transition process,which may prelude to a new class of generalized turbulence model for engineering applications.更多还原