基于非结构网络的翼身组合体绕流数值模拟

【作者】 段卓毅；

【导师】 乔志德；

【作者基本信息】 西北工业大学 ， 流体力学， 2001， 硕士

【摘要】 非结构网格的生成与应用推动了CFD技术的发展，它使得针对复杂外形的网格生成变得相对容易。通过控制背景网格，使非结构网格的尺度及疏密分布随物面几何外形易于调整，与结构化网格相比，针对复杂外形的非结构网格质量的根本改善大大提高了复杂外形绕流的流场计算精确度，这一网格生成方法已经显示出是一种强有力的CFD技术。本文工作正是在这一技术发展背景下开展的。论文的工作包括以下几个方面： （1）应用投影变换的方法生成了三维翼身组合体的表面网格。 （2）对决定三维非结构网格生成结果及疏密分布的背景网格生成技术做了深 入细致的研究，采用了三维空间多层背景网格，它是结合结构化Cartesian 和非结构背景网格各自优点的背景网格生成方法，通过本文实践证明，该 方法是成功的。 （3）由生成的三维初始推进面，应用推进阵面法完成了翼身组合体的三维空 间网格生成并尝试了一种新的推进选点准则，实践证明是可行的。应用网 格光顺技术，改进了初始生成的网格质量。 （4）应用格心格式的有限体积法对翼身组合体绕流进行了Euler方程的数值 模拟，同时引入各种加速收敛措施，与实验相比，得到了较为满意的计算 结果。 本文的工作表明，非结构网格生成及应用在计算流体力学中具有良好的发展前景。更多还原

【Abstract】 The Computational Fluid Dynamics (CFD) has been rapidly developed with the application of unstructured grids which makes it easier to generate the grids for complex geometries by controlling the background girds , it is pretty easy to refine the size and distribution of unstructured grids The computation accuracy of flow over complex geometries can be greatly enhanced due to the improvement of grid quality . The method has been shown that it is a very powerfiil technique for CFD.This paper presents some works based on the unstructured grids, the main works of the paper are as follows:1)generating the surface unstructured grids for combination of wing-body by means of projection transformation2)A multi-domain method of grid generation is adopted to control quality and distribution of the unstructured grids , the method combines the advantage of both structured Cartesian and unstructured background grids.3)generating the 3-D unstructured grids for the combination of wing-body by means of AFM (Advancing Front Method ) . using a new criterion for selecting the optimum point . The method is proved to be feasible . The grid quality is better than original method by means of deleting some small and distorted?elements and smoothing technique.4)the EULER equation is solved for the combination of wingbody by means of the finite volume method on the unstructured grids . Several methods are used for quick convergence and the results are in correspondence with the experiment data.What is done in the paper shows that the unstructured grid has the great potential power and it will be more widely used in the Computational Fluid Dynamics (CFD) in the future.更多还原