基于模型验证与确认方法的空爆自由场网格敏感性分析  

Analysis on Grid Sensitivity of Free Field of Air Explosion Based on Verification and Validation(V&V)Method

作　　者：陈博[1] 仵可 张云峰 随亚光[1] CHEN Bo;WU Ke;ZHANG Yunfeng;SUI Yaguang(Northwest Institute of Nuclear Technology,Xi’an710024,China;Xi’an Research Institute of High-tech,Xi’an 710025,China)

机构地区：[1]西北核技术研究所,西安710024 [2]西安高新技术研究所,西安710025

出　　处：《现代应用物理》2024年第3期148-157,共10页Modern Applied Physics

摘　　要：为能够在合理计算规模下准确模拟空爆自由场冲击波特征的网格划分方案,获得可靠的计算结果,本文运用验证与确认(verification and validation,V&V)方法,通过开展网格敏感性分析,确认了炸药空爆计算模型的数值解、外推估值、网格收敛指标与比例距离的定量关系,给出了满足不同网格收敛指标要求的最大比例网格尺寸随比例距离位置的变化关系。据此,在比例距离Z为0~40 m·kg^(-1/3)范围内,给出了划分渐变网格的优化方案。针对1维、2维、3维计算模型,分别比较了细网格、粗网格、渐变网格方案的计算精度与计算耗时情况,讨论了本文提出网格划分方法的适用性。同时,采用本文建议的网格优化方案,给出了动爆冲击波毁伤飞机数值模拟场景的应用算例。结果表明,本文建议的网格优化方案可在几乎不降低计算精度的前提下显著提升计算效率,可为空爆自由场或者近似计算场景的数值模型网格划分提供参考。To get a grid scheme which can accurately simulate the physical properties of the blast shockwave from a free-field air explosion for a reasonable numerical solution,this paper obtained the palpable results by conducting grid sensitivity analysis with the verification and validation method.The numerical solution,extrapolation estimate,and quantitative relationship between the mesh convergence index and the proportional distance of the calculation model of the air blast wave,are confirmed.The curves of the maximum proportional mesh size varying with the position of the proportional distance satisfying the requirements of different mesh convergence index is given.Accordingly,in the range of Z=0-40 m·kg~(-1/3),the optimization scheme of gradient grid division is given.For one-dimensional,two-dimensional,three-dimensional computing models,the calculation accuracy and calculation time of fine grid,coarse grid and gradient grid scheme are compared respectively.The applicability of the proposed meshing method is discussed.At the same time,using the grid optimization scheme proposed in this paper,an application example of the dynamic explosion shockwave damage of aircraft by numerical simulation is given.The results show that the grid optimization scheme proposed can significantly improve the calculation efficiency without reducing the calculation accuracy,and provide a reference for the numerical model meshing of the air blast shockwave of free-field or the approximate calculation field.

关 键 词：V&V方法 计算效率 网格敏感性 冲击波 自由场 

分 类 号：O38[理学—流体力学] TL99[理学—力学]