Modeling of Natural Transition in Properly Three-Dimensional Flows
Modeling of Natural Transition in Properly Three-Dimensional Flows
复制标题
正确三维流动中自然过渡的建模
作者：
M. Arthur
本文描述了一种粘性流动预测方法，其中包括作为计算的一个组成部分的转折起始位置的预测。该方法与其他方法的相似之处在于，它基于边界层的稳定性分析，但承认在使用常规网格尺寸时，雷诺平均N-S方程(RANS)的解产生的边界层精度不够高。因此，通过求解层流边界层方程，边界层被重新计算到高精度。由稳定性分析确定的过渡起始位置被传递回RANS解算器以进行进一步迭代。本文所描述的方法与其他方法的不同之处在于，层流边界层的计算是全三维的，稳定性分析是通过可压缩流动的全三维抛物化稳定性方程进行的。计算结果表明了层流边界层方法的能力和求解抛物化稳定性方程的有效性。此外，通过对AFRL 1303 UCAV概念的粘性流动的计算，初步验证了全三维层流边界层和稳定性分析分量可以成功地与RANS方法相结合来计算有自然过渡的流动。
The paper describes a method for viscous flow prediction which includes the prediction of transition onset location as an integral part of the calculation. The method is similar to others in that it is based on stability analysis of the boundary layers but acknowledges that solutions of the Reynolds-averaged Navier-Stokes (RANS) equations yield boundary layers of in adequate accuracy w hen conventional mesh sizes are used. The boundary layers are therefore recomputed to high accuracy by solving the laminar boundary layer equations. Transition onset locations determined by the stability analysis are passed back to the RANS solver for further iterations. The method described in this paper differs from others in that the laminar boundary layer calculation is fully three-dimensional and the stability analysis is through the fully three-dimensional parabolised stability equations for compressible flow. Results are presented to illustrate the capability of the laminar boundary layer method and the effectiveness of the method for solving the parabolised stability equations. In addition, preliminary validation results are presented from calculations of the viscous flow over the AFRL 1303 UCAV concept to demonstrate that the fully three-dimensional laminar boundary layer and stability analysis components can be combined successfully with a RANS method for calculating flows with natural transition.