Navier-Stokes方程数值模拟及湍流模型研究

【作者】 李杰；

【导师】 白俊强；

【作者基本信息】 西北工业大学 ， 飞行器设计， 2006， 硕士

【摘要】 本文开展了代数法结合源项修正技术的偏微分方程法的网格生成技术研究,在此基础上,应用有限体积法,采用中心差分格式的空间离散方法和显式的Runge-Kutta时间推进方法对Navier-Stokes方程进行求解,并编制了相应的计算程序。为了验证程序的适用性,分别对M6机翼和F4翼身组合体粘性流场进行了数值模拟。 在网格生成方面,首先采用二维椭圆型偏微分方程方法逐个生成三维外形的截面和子午面网格,然后利用代数方法将这些截面或子午面网格采取堆砌的方法生成整个三维网格,这种方法将三维网格的生成转化为二维网格的生成,大大降低了网格生成难度,而且保证物面区域网格的正交性。 在流场求解方面,本文采用改进的Jameson中心+人工粘性格式,应用了各向异性人工粘性和修正的压力(温度)感测因子方法,在解决由于中心格式固有的奇偶失联问题的同时,很大程度的减小了人工粘性对真实物理粘性的影响。湍流模型方面引入Baldwin-Lonax(B-L)湍流模型和Spalart-Allmaras(S-A)湍流模型,同时采用当地时间步长,隐式残值光顺等加速收敛措施。 对M6机翼和F4翼身组合体粘性流场进行了模拟,并对选用两种湍流模型的计算结果进行了比较。计算实例表明:本文结构网格的生成技术和流场的计算程序都是比较成功的,满足一定的数值求解精度,具有工程技术应用价值。更多还原

【Abstract】 In this thesis a strategy for the generation of hexahedron structured viscous grid on three-dimensional configurations has been introduced, based on the method. We made the code to calculate the 3-D N-S equation using Runge-Kutta time stepping scheme, and viscous flows around M6 wing and F4 wing-body configuration are simulated to test the applicability of the code.Solving the elliptic grid generation together with an algebraic method , we generate 2-D grid along the meridian of the body used Higenstock source correct technical. and adjust them to be 3-D grid smoothly using an algebraic method. Though viscous grids around the geometries are generated. The advantage of the method is easy and it can keep the grid as rigid as possible in the near-wall regions.In order to simulate the flow field, 3-D N-S equations are solved using the cell-centered finite volume spatial discritization and four-stage Runge-kutta time stepping scheme on structured viscous mesh with standard convergence acceleration techniques such as local time stepping and implicit residual smoothing. In this paper, an correctional press sensor and anisotropy artificial viscosity was used to reduce the affect of the physical viscosity that traditional artificial viscosity do. We use the B-L and S-A turbulent model to simulate the viscous affect, and the two different result was compared in the end, Based on the above work, structured laminar solutions on the M6 wing and wing-body configuration have been achieved.The results of grid generation indicate that the gird generation approach is reasonable in handling three-dimensional configurations. The results of flow field computation are in good agreement with the experiments, which show that the numerical solution method is correct and robust.更多还原