发展能自动随网格尺度变化而光滑切换物理模型的多尺度方法具有非常重要的理论研究和工程应用价值。对湍流这种典型多尺度流动问题它能有效兼顾有限计算资源和流动精细模拟需求。本项目基于介观气体动理论，发展一种可压缩湍流新型多尺度模拟方法。研究内容包括：发展和改进已有高精度气体动理学格式，提高格式的精度和分辨率；利用拓展BGK方程的跨尺度演化解，构造多尺度湍流模拟新框架，结合已有RANS和LES模型加以验证，并应用到典型高雷诺数工程湍流精细模拟；从气体动理论出发，结合典型流场数据，改进和发展湍流模型。

It is important for either theoretic studies or engineering applications to develop a multiscale method which can achieve smooth transition between physical models according to computational cell size. It is capable of effective balancing the limited computational resource and the requirement of fine simulation in the investigation of multiscale flow such as turbulence. The objective of present proposal is to develop a new multiscale method for compressible turbulence simulation, based on the mesoscopic gas-kinetic theory. The research includes three parts. The first is the improvement of existing high-order accurate gas-kinetic scheme to further increase the accuracy and resolution. The second part is to construct a new framework for multiscale simulation of turbulence with the help of cross-scale evolution solution of the expanded BGK equation, and then combine it with traditional RANS and LES models for validation and application in typical high-Reynolds-number flow. The last part of the present study is the development of turbulence model based on gas-kinetic theory and flow field data from direct numerical simulation.