DIFFERENTIAL DISTANCE FUNCTION COMPUTATIONS FOR MESH GENERATION

网格生成的差分距离函数计算

• 批准号: EP/E057233/1
• 负责人: Paul G. Tucker
• 金额: $ 34.18万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE057233%2F1
• 关键词: DIFFERENTIAL; DISTANCE; FUNCTION; COMPUTATIONS; MESH

Essentially, distance functions (raw and modified nearest surface distances) are needed for RANS (Reynolds Averaged Navier-Stokes) turbulence modelling, general computational interface tracking for multiphase and free surface flows, electrostatic Coulomb force modelling and also flame front and explosion modelling along with ray tracing for optics and acoustics. They can also be used to capture Knudsen layer effects in microscale flows and for the implementation sponges and various other numerical wave reflection damping strategies and stabilising measures for LES (Large Eddy Simulation). Furthermore they can be used to implement hybrid LES-RANS strategies. Distance functions, can under certain circumstances be evaluated using expensive search operations. Alternatively, differential equations can be solved. Here, it is proposed to explore the solution of differential distance function equations on unstructured (where a wide range of cell shapes can be tessellated in a flexible fashion) moving and overset meshes to yield the above noted capabilities which are highly desirable for general purpose CFD codes. Flow solutions using such grids are increasingly common. However, robust mesh generation still presents a significant challenge. This is especially so if use is made of hexahedral cells and the higher numerical fidelity that they provide. Hence, here it is proposed to also explore the use of novel differential distance function related equation based approaches for: hybrid grid generation (hexahedral boundary layer cells linked to tetrahedral cells outside the boundary layer); pure hexahedral grid generation and overset grid computational interface location. The differential equations explored will include the hyperbolic Eikonal, Hamilton-Jacobi and elliptic Poisson. Especial attention will be paid to the economical and accurate solution of these equations on moving, unstructured over-set grids with mixed element topologies using finite element, finite volume & boundary element methods.

本质上，RANS（雷诺平均纳维尔-斯托克斯）湍流建模、多相和自由表面流的一般计算界面跟踪、静电库仑力建模以及火焰前缘和爆炸建模沿着光学和声学的射线跟踪都需要距离函数（原始和修改的最近表面距离）。它们还可以用于捕获微尺度流动中的努森层效应，以及用于实施海绵和各种其他数值波反射阻尼策略和LES（大涡模拟）的稳定措施。此外，它们可以用来实现混合LES-RANS策略。在某些情况下，距离函数可以使用昂贵的搜索操作进行评估。或者，可以求解微分方程。在这里，建议探索非结构化（其中可以以灵活的方式镶嵌各种单元形状）移动和重叠网格上的微分距离函数方程的解，以产生通用CFD代码非常需要的上述能力。使用这种网格的流动解决方案越来越普遍。然而，强大的网格生成仍然提出了一个重大的挑战。如果使用六面体单元和它们提供的更高的数值保真度，则尤其如此。因此，在这里，它建议也探索使用新的微分距离函数相关的方程为基础的方法：混合网格生成（六面体边界层细胞连接到四面体细胞外的边界层）;纯六面体网格生成和重叠网格计算接口的位置。探讨的微分方程将包括双曲程函，哈密尔顿-雅可比和椭圆泊松。将特别注意这些方程的经济和准确的解决方案，移动，非结构化重叠网格与混合元素拓扑结构，使用有限元，有限体积和边界元方法。

项目成果

Fast distance solution for medial axis transform

中轴变换的快速距离解

• 发表时间: 2009
• 作者: H Xia

Level sets for CFD in aerospace engineering

• DOI: 10.1016/j.paerosci.2010.03.001
• 发表时间: 2010-10
• 期刊: Progress in Aerospace Sciences
• 影响因子: 9.6
• 作者: H. Xia;P. Tucker;W. Dawes

Differential equations for generating multiblock mesh partitions

用于生成多块网格分区的微分方程

• 作者: Paul G. Tucker (Co-Author)

Hybrid Hamilton-Jacobi-Poisson wall distance function model

混合 Hamilton-Jacobi-Poisson 壁距离函数模型

• DOI: 10.1016/j.compfluid.2010.12.021
• 发表时间: 2011
• 期刊: Computers & Fluids
• 影响因子: 2.8
• 作者: Tucker P

Numerical Study of Chevron Jet Noise Using Parallel Flow Solver

使用并行流求解器对 Chevron 喷射噪声进行数值研究

• DOI: 10.1016/j.proeng.2013.07.090
• 发表时间: 2013
• 期刊: Procedia Engineering
• 作者: Xia H