基于两相流欧拉方法的翼型结冰数值模拟

Applying Eulerian Droplet Impingement Model to Numerically Simulating Ice Accretion but with Some Improvements

文章通过计算流体力学的方法对翼型结冰进行了预测。针对拉格朗日法求解水滴收集特性计算工作量太大的缺点,引入水滴流场的概念,通过求解空气-水滴两相流场的欧拉方法,获得翼型表面水滴收集特性。结冰计算过程中网格采用变形网格技术得到,既保证了网格质量又减少了网格生成的工作量,采用有限体积法及LU-SGS隐式时间推进数值求解N-S及水滴运动方程。建立了对应于霜冰和光冰的冰增长模型。通过对NACA0012翼型霜冰和光冰的计算验证了该方法是有效的。

Aim. We apply the model employed by Refs. 3,4 and 5 but differ from their method in that we employ several approximate unsteady processes instead of their several quasi-steady processes. Section 1 of the full paper explains how to generate the initial computational grid by solving elliptic equations and by employing the modified TFI method based on the interpolation of block comer displacements during the grid deformation per time step in unsteady flow simulation. Section 2 uses the Eulerian two-phase flow model for the air flow containing water droplets to compute the trajectories of the water droplets. Its core consists of： （ 1 ） we solve the Navier-Stokes （N-S） equations with a conventional algorithm, which includes cell-centered finite volume method and a fully implicit solver based on LU-SGS and which completes the solution of the N-S equations by introducing the B-L algebraic turbulence model; （2） using the above methods, we present numerical results in Fig. 2. Section 3 explains the calculation of ice shape; its core is that we determine the ice shape with the assumption that all droplets freeze at their points of impact and that the ice grows in the direction normal to the surface. The computational results, presented in Figs. 3 through 8, are in good agreement with the available experimental data, thus showing preliminarily that the application of the existing Enlerian droplet impingement model, but with some improvements proposed by us, to numerically simulating ice accretion is indeed feasible.