非结构混合网格在气动热标模模拟中的应用

非结构混合网格消除了结构网格节点的结构性限制,可以较好地处理边界,同时兼顾了粘性边界层模拟的需求,具有灵活性大、对复杂外形适应能力强和生成耗时短等优点,在飞行器气动特性模拟中得到广泛应用.本文针对非结构混合网格的特点,把前期针对非结构混合网格气动力高精度模拟发展改进的梯度计算方法和Roe格式熵修正方法推广应用到气动热流的数值模拟.以典型钝锥标模外形的高超声速绕流为研究对象,开展了不同网格形式和第一层网格不同间距的影响研究.结果 表明,热流计算时,头部物面网格最好采用四边形或四边形交叉剖分得到的三角形网格,物面法向的网格雷诺数取20左右,为热流计算时非结构混合网格的生成提供了指导,同时验证了计算方法的有效性和可靠性.

Application of unstructured hybrid grid on the aerothermodynamics prediction for calibration model

An unstructured hybrid grid eliminates the structural constraints of nodes for a structured grid,so it can deal with the boundary well.At the same time,it takes into account the needs of viscous boundary layer simulation,and has the advantages of flexibility,strong adaptability to complex shapes and short generation time.It has been widely used in the simulation of aircraft aerodynamics.According to the characteristics of unstructured grids,the improved methods of gradient calculation and entropy correction of Roe scheme,which were developed for high-precision aerodynamic analysis using an unstructured hybrid grid in the previous stage,are extended to the numerical simulation of aerothermodynamics.Taking the hypersonic flow around the blunt cone calibration model as the research object,the effects of different grid forms and the first layer mesh distance are studied.The research results show that:when calculating aerothermodynamics,it is best to use the quadrilateral mesh or triangular mesh obtained by cross dividing quadrilateral mesh,and the normal grid Reynolds number of the surface is about 20.The research provides guidance for the generation of unstructured hybrid grids in aerothermodynamics prediction,and verifies the effectiveness and reliability of the calculation methods.