摘要:
本研究建立了适用于可压缩边界层转捩问题的高精度数值模拟方法及并行算法;对平板、圆锥、复杂边界层等超声速流场进行了流动稳定性分析;建立和完善转捩预测方法,建立转捩准则;对用于高马赫数、高雷诺数高速飞行器边界层的工程湍流模型进行了改进;进行了高温效应对高超声速边界层转捩位置的影响及旁路(bypass)转捩机理的研究.此外,以e-N方法为基础,集成了用于一般可压缩边界层的流动稳定性分析及转捩预测的程序,为复杂流动问题及工程问题提供了有力的分析手段.面向可压缩湍流的直接数值模拟,开展了数值方法研究,构造了系列高精度、高分辨率数值方法.在此基础上对可压缩平板、钝锥、槽道、压缩折角、入射激波-平板湍流边界干扰等问题进行了直接数值模拟.形成的湍流数据库为湍流机理及模型研究提供了有力支持.在此基础上对压缩性效应、壁温效应、激波-湍流边界层干扰等流动机理以及流动控制手段进行了研究.以湍流数据库为基础对湍流模型及大涡模拟模型进行了评估和改进.同时还开展了湍流燃烧的大涡模拟研究.形成了一套开放的高精度CFD程序,为复杂流动问题以及工程流动问题的计算提供了有力手段.%Transition of boundary layer is the most important process in the typical flows past flying vehicles because the correct computation of the drag and surface heat flux depends on the correct prediction of the transition location. The accurate computation of turbulence is a difficult problem for fluid mechanics, and is a key problem for engineering as well. We investigated the transition mechanism of compressible flow and turbulent characteristics of the typical flows past flying vehicles, based on which the physical mechanism behind is studied. We proposed high precision numerical simulation method and parallel method, which are suitable for problem of transition in compressible boundary layers. We did stability analysis for supersonic boundary layers on flat plate, cone and some complex geometry case as well. We proposed transition criterion and improve the method for transition prediction. And the turbulent model for high Mach number and high Reynolds number flows is improved. We found the influence of high temperature gas on transition location and investigate the mechanism in bypass transition. Furthermore, we developed a universal code to analyze the stability characteristics and predict transition locations for general compressible flows, which becomes an effective method for complex flows in industries. For the direct numerical simulation of compressible flows, we proposed a series of high-precision, high-resolution numerical method. And based on that, the direct numerical simulations are performed on compressible flat plate, blunt cones, channel flows, compression ramp flows, interaction between shock and turbulent boundary layers. The database constructed is effective support for investigation of turbulence mechanism and model. We investigate the effect of compression, temperature on the wall, interaction between shock and turbulent flow, flow control method and the turbulence combustion. We developed an open high precision CFD code, which is effective for computation of flows in industries. The above achievements have directly supported the development of the major projects in our country.