可压缩螺旋湍流的基本理论与应用研究

可压缩螺旋湍流广泛存在于超新星爆炸、星系密度云演化以及高超声速飞行器外部流动、航空发动机内流、热核聚变湍流混合等自然及工程流动中。可压缩条件下手性的破缺带来更复杂的流动结构及波涡相互作用等新的物理现象，本项目在已有的不可压螺旋湍流及不考虑螺旋度效应的可压缩湍流的研究基础上，同时考虑强压缩性、手性破缺以及各向异性等因素的影响深入研究湍流结构演化及不同尺度上的湍流统计特性。重点研究强压缩条件下动能及螺旋度联合级串在物理空间的尺度交互局部性问题、多尺度多方向传输；能量级串与螺旋度级串相互作用规律；壁湍流中能量与螺旋度联合级串的空间尺度分布以及对可压缩湍流动力学过程的影响。拟开展超大规模可压缩螺旋湍流直接数值模拟，采用多尺度滤波、广义螺旋波分解以及多尺度梯度展开等分析手段研究可压缩螺旋湍流的内在物理规律，并应用所得到的基础理论为可压缩湍流大涡模拟模型的建立提供有效的解决方案。

Compressible helical turbulence exists widely in natural phenomena and engineering flows, such as supernova explosion, evolution of galaxy density cloud , external flow of Hypersonic vehicle, internal flow of aero-engine, turbulent mixing of inertial confinement fusiondesign, etc. On the basis of the existing studies on incompressible helical turbulence and compressible turbulence ignoring the helicity effect, this fund conducts an in-depth study on the statistical characteristics of turbulence with different scales under the influence of strong compressibility, chiral breakage and anisotropy. The research will focus on the problem of locality of scale interaction and multi-scale and multi-direction transmission of the joint cascade of kinetic energy and helicity in physical space under strong compressibility, the law of the interaction between energy cascade and helicity cascade, spatial scale distribution of joint cascade of energy and helicity in wall turbulence and its influence on the dynamic process of compressible wall turbulence. Superlarge-scale direct numerical simulation of compressible helical turbulence will be carried out, and the internal physical laws of helical turbulence will be studied by means of multi-scale filtering, general helical wave decomposition, helical wave decomposition, multi-scale gradient expansion, etc. Then, the new physical laws from compressible helical turbulence will be applied to modify or build new compressible large-eddy simulation model.