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ABSTRACT In this paper, we present a systematic roadmap for developing a robust and parallel multi-material reactive hydrodynamic solver that integrates historically stable algorithms with new and current modern methods to solve explosive system design problems. The Ghost Fluid Method and Riemann solvers were used to enforce appropriate interface boundary conditions. Improved performance in terms of computational work and convergence properties was achieved by modifying a local node sorting strategy that decouples ghost nodes, allowing us to set material boundary conditions via an explicit procedure, removing the need to solve a coupled system of equations numerically. The locality and explicit nature of the node sorting concept allows for greater levels of parallelism and lower computational cost when populating ghost nodes. Non-linear numerical issues endemic to the use of real Equations of State in hydro-codes were resolved by using more thermodynamically consistent forms allowing us to accurately resolve large density gradients associated with high energy detonation problems at material interfaces. Pre-computed volume tables were implemented adding to the robustness of the solver base. 相似文献
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推导了轴对称几何下的MOF(Moment of Fluid)界面重构,将其与多介质ALE方法相耦合,形成MOFMMALE方法,并应用于多介质大变形流动问题的数值模拟研究。数值算例表明,耦合MOF界面重构的多介质ALE方法是求解多介质大变形流动问题的有效手段,并且具有很好的界面精度和分辨率。 相似文献
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提出了一种基于水平集的Eulerian-Lagrangian耦合方法,其中Lagrangian方法采用相容显式有限元拉氏方法,Eulerian方法采用基于近似Riemann解的有限体积Eulerian方法,多介质界面处理采用新的水平集和Ghost方法计算. 给出了若干数值算例,包括激波管问题以及金属和气体的运动界面及其大变形问题,并分别与精确解和相容显式有限元拉氏方法的计算结果进行了对比. 数值结果表明,该方法计算结果正确,精度较高,能够准确捕捉物质界面,适用于处理大变形问题. 相似文献
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聚能射流三维数值模拟 总被引:5,自引:0,他引:5
研究三维多介质界面处理及数值模拟问题。采用拉格朗日法、欧拉法相结合的方法在矩形网格上离散差分基本方程组;在欧拉步中引入模糊方法处理界面,计算各输运量;编写了数值模拟程序,并对线型装药金属罩聚能射流模型进行模拟。证明模糊界面描述和模糊输运计算有效、可行。 相似文献
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In the present paper the elastostatic problem of a generally anisotropic and angularly inhomogeneous plane wedge loaded at its apex by a concentrated force, is studied in linear elasticity. At first the self-similarity property is formulated and the stress field of the inhomogeneous anisotropic self-similar wedge problem, is deduced. The wedge is radially separated and the plane wedge problem is reformulated by the introduction of a characteristic vector. Furthermore, the angular distribution of the load is determined. The multi-material wedge problem in terms of a formulation based on the isotropic angularly inhomogeneous wedge, is confronted, and necessary conditions that ensure the self-similarity property, are found. Finally, the similar elastostatic wedge problems and the involution between stresses, are studied.
Mathematics Subject Classifications (2000) 74B05, 74K30, 34B05, 51N15. 相似文献
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This work introduces a method for the exact solution of initial–boundary value problems for linear, one-dimensional conservation laws in multi-layered, multi-material domains. The method is based on the geometry of the solutions of such conservation laws and represents an extension of the d’Alembert solution to initial–boundary value problems in multi-layered, multi-material domains. 相似文献
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Yibing Chen Junxia Cheng Liang Pan Haihua Yang Heng Yong & Xin Yu 《高等学校计算数学学报(英文版)》2021,14(1):219-241
Hydrocodes are necessary numerical tools in the fields of implosion and high-velocity impact, which often involve large deformations with changing-topology interfaces. It is very difficult for Lagrangian or Simplified Arbitrary Lagrangian-Eulerian (SALE) codes to tackle these kinds of large-deformation problems, so a staggered Multi-Material ALE (MMALE) code is developed in this paper, which is the explicit time-marching Lagrange plus remap type. We use the Moment Of Fluid (MOF) method to reconstruct the interfaces of multi-material cells and present an adaptive bisection method to search for the global minimum value of the nonlinear objective function. To keep the Lagrangian computations as long as possible, we develop a robust rezoning method named as Combined Rezoning Method (CRM) to generate the convex, smooth grids for the large-deformation domain. Regarding the staggered remap phase, we use two methods to remap the variables of Lagrangian mesh to the rezoned one. One is the first-order intersection-based remapping method that doesn't limit the distances between the rezoned and Lagrangian meshes, so it can be used in the applications of wide scope. The other one is the conservative second-order flux-based remapping method developed by Kucharika and Shashkov [22] that requires the rezoned element to locate in its adjacent old elements. Numerical results of triple point problem show that the result of first-order remapping method using ALE computations is gradually convergent to that of second-order remapping method using Eulerian computations with the decrease of rezoning, thereby telling us that MMALE computations should be performed as few as possible to reduce the errors of the interface reconstruction and the remapping. Numerical results provide a clear evidence of the robustness and the accuracy of this MMALE scheme, and that our MMALE code is powerful for the large-deformation problems. 相似文献