一种非结构结构多层混合网格方法及其应用

An Unstructured/structured Multi-layer Hybrid Grid Method and Its Application

对于粘性绕流的数值模拟,在自适应直角网格基础上,结合三角形非结构网格和结构化网格,利用其各自的优势和特点,提出一种生成混合杂交网格的思路和方法.在物面附近生成适合粘性流计算的大长宽比结构化网格,在远场分布自适应直角网格,快速离散计算空间.对于复杂的多体问题,采用三角形网格来连接各体网格,并运用网格合并的方法,保证各网格之间的光滑过渡与连接,提高网格质量.针对一些二维、三维外形的绕流问题,在上述网格基础上,采用B-L代数湍流模型和中心有限体积法,完成Navier Stokes和Euler方程数值模拟的对比计算,结果表明网格生成和流场计算是正确的.

A multi-layer hybrid grid method is constructed to simulate complex flow field around 2-D and 3-D configuration.The method combines Cartesian grids with structured grids and triangular meshes to provide great flexibility in discretizing a domain.It generates the body-fitted structured grids near the wall surface and the Cartesian grids for the far field.In addition,the triangular meshes are regarded as an adhesive to link each part of grids.The grid combination methodology is discussed,which can smooth hybrid grids and improve the quality of the grids.A uniform type of data is defined to manage and arrange grid data.Using the centered finite volume method,the inviscid and viscous flow allows computation by solving the Euler and Navier-Stokes equations.The computational results prove that grid generation and flow calculation are correct and feasible.