LS-DYNA ALE方法和流固耦合

LS-DYNA 多材料ALE方法在模拟流体及流固耦合中被广泛使用。 尽管在平流过程中,ALE方法会带来额外的数值误差,多材料ALE方法仍然可以成功的模拟一系列 工程流体问 题。 这些问题中流体通常带着很大的动量或能量而冲击或穿透固体结构。 例如,爆炸,油箱晃动,液体包装跌落,飞鸟冲击,子弹穿透等。

本课程力图为用户提供一个了解LS-DYNA任意拉格朗日欧拉方法和流固耦合的途径。参与培训的用户需要有对有限元法和对LS-DYNA的基本了解(能对小问题建模,执行,后处理分析的能力)。 对有限元法和计算流体力学的深入了解是有帮助的,但绝非必需。

课程将首先简要介绍有限元法和显式分析的几个重要概 念。 接下来我们介绍多材料ALE的两个关键部分,平流过程和用来描述单元内材料界面位置的界面重构法。 在第一天的最后,我们将介绍网格移动。 网格移动与 否是欧拉法和ALE法的分界。

第二天我们以流固耦合部分的介绍开始。 我们将用一个简单的接触问题来与流固耦合相比较。 接下来我们将介绍流固耦合的各个主要要素,如流体液面构建,固体表面,惩罚弹簧,泄漏等等。 一些影响流固耦合的关键点也将被讨论。 接下来的时间我们将主要讨论工程应用和建模方法。

LS-DYNA Multi-material ALE has been used extensively to model fluids in contact with structures. Despite the numerical error introduced in the advection process, it is well suited to simulate a series of engineering problems that involve fluids carrying large momentum or high energy density impacting, penetrating Lagrange structures. For examples, explosions, tank sloshing, container dropping, bird strike, projectile-hitting-target, etc.

This course aims to provide an understanding of ALE method and its FSI capabilities. Class attendants are expected have an understanding of finite element method and a basic knowledge of LS-DYNA package (be able to construct, execute and analyze a simple Lagrange structure model). Advanced knowledge in finite element method and computational fluid dynamics is helpful but not necessary.

We will start with a brief introduction to finite element method and cover certain key concepts in explicit analysis. Next we explain the two essentials in the Multi-material ALE formulation: the advection process and interface reconstruction algorithm used to model intra-element fluid interfaces. Mesh motion is covered to wrap up the ALE part and the first day of the class.

The second day we continue with the fluid structure interaction part. We start with a simple contact case as it is more familiarized with LS-DYNA users. By comparing the contact and coupling algorithms, we smooth our entrances to the ALE FSI concepts. Next we cover several aspects of the coupling method, such as construction of fluid interface and structure interface, penalty spring, leakage, etc. Key points of performing a successful FSI analysis are then discussed. We conclude the class by familiarizing attendants of different types of applications and their modeling techniques.




2 days





主要内容(Main Contents):

  • 有限元方法概述   Overview of Finite Element Method
  • 波传播与显式分析   Wave propagation and explicit analysis
  • 平流过程与界面重构  Advection and interface reconstruction
  • 网格移动  Mesh motion
  • 流固耦合  Fluid structure interaction
  • ALE/FSI建模方法  ALE/FSI modeling
  • 应用  Applications

  • 培训课程专家(Instructor):

    陈皓/ Hao Chen 博士毕业于西北大学,从2004 年至今,在LSTC 从事任意拉格朗日欧拉方法(ALE)及流固耦合(SFI)的开发和工程问题应用。