1208 Industrial Application of Particle Methods

  • Sunao Tokura, Prometech Software Inc.
  • Massimo Galbiati, Particleworks Europe
  • Brant Ross, EnginSoft USA
  • Mamika Kawahara, Kozo Keikaku Engineering, Inc.

Since the latter half of the 20th century, with the evolution of computers, numerical computation methods based on spatial and time discretization have been put into practical use as a means for simulating actual physical phenomena. In the field of solid mechanics represented by structural analysis, mainly, the finite element method (FEM) based on Lagrangian formulation, in which the mesh deforms as the material deforms, has been developed to evaluate the deformation, stress, and strain of the material. In the field of fluid mechanics, the finite difference method (FDM), which is a discretization method based on Eulerian formulation, in which fluid flows in the mesh fixed in space, has been developed. These analysis methods were initially applied to simple problems and then to gradually complex problems, and various enhancements were made accordingly. For the FEM, various developments have been made which include, linear analysis, nonlinear analysis for material, geometry and boundary condition, combination with fracture mechanics, static and dynamic problem, impact problem, and so on. For the FDM, it is possible to trace the development process such as incompressible flow to compressible flow, laminar and vortex to turbulent flow, shock wave, single-phase flow to multiphase flow, and Newtonian viscosity to various non-Newtonian viscosity models. Both analysis methods have been developed through the process from the modeling of ideal solids and fluids in the early stage to the modeling of the properties and phenomena of real materials, but it is considered that the major driving force of the development was the use for product development in various manufacturing industries. Until then, product development has generally been a process of predicting the expected performance of a product by applying limited theory and empirical formulas and experiments that simplify actual events and then repeating trial production and improvement based on that. On the other hand, numerical simulation by FDM and FEM brought a revolutionary change in the design and development of products and contributed to the improvement of quality and performance of all products. That trend continues to this day. However, in order to faithfully reproduce the situation in which a product is placed in the real world, it is necessary to replace multiple physical phenomena with numerical models. In such an attempt, it has been recognized that there are some events in which it is difficult to apply the spatial discretization method using the mesh topology such as FDM and FEM. There are many problems where, it is not theoretically impossible to compute by increasing the mesh resolution, but the computation cost becomes enormous and practically impossible to compute. Therefore, research on mesh-free solutions that do not depend on mesh connectivity has been continuously conducted from the last few decades of the last century to the present day. The particle method can be considered as one of them. "Mesh-free" means that the complicated and time-consuming work of mesh generation, which has been part of the pre-processing work of simulation model preparation, becomes unnecessary. And, even if the "particle" in the particle method does not always represent the actual particle and is only a calculation point for numerical computation, the procedure, in which the continuum is approximated by a set of particles, and the shape change of it is tracked by Lagrangian manner, is very intuitive. It can be said that the particle method is a solution technique that is easy to accept even for engineers who do not specialize in numerical computation. These features are important for engineers who are involved in product design and development. The particle method inherits the discretization method from the mesh-based computation method, and has the advantage that it can be easily applied to problems to which the conventional method was difficult to apply. On the other hand, given the problem peculiar to the particle approximation that presupposes irregular arrangement, further research is needed, such as a highly accurate discretization scheme that does not depend on particle arrangement and a technique of setting boundary conditions. The particle method is expected to become more important not only in academic research fields but also in various industrial fields as a numerical solution method that complements the conventional mesh-based computation method. Numerical simulation is positioned as the third method along with theory and experiment as a method for evolving and developing science and technology. The particle method has already gone beyond the scope of academic research, and many commercial CAE software based on the particle method have been developed and play an important role in actual manufacturing. This mini-symposium targets the industrial application of the particle method, introduces cutting-edge application examples of the particle method used in various industries, and gives an outlook of the future evolution of the particle method. Some examples will show the benefits of applying particle methods in combination with the simulation of other physics. This symposium provides a place for researchers, software developers, and users to make recommendations and discussions from their respective standpoints.

© WCCM-APCOM 2022. All Rights Reserved.