Generalized anisotropic/isotropic porous media flows in ls-dyna

Abstract

Among the current needs of large industries and engineering companies is the ability to perform numerical simulations of complex processes that require the coupling of multiple fields, each representing a different physical model and/or phenomena. Processes involving fluid flows through porous media matrices are present in a wide range of these kind of problems. In the ground vehicles industry, understanding aerodynamics phenomena allows us to optimize the operation of a wide spectrum of road vehicles, that ranges from road passenger transport (cars, buses, trains) to road commercial transport (trucks and trains). Road vehicle aerodynamics is a complex topic due to the interaction between the air flow and the ground and some parts (that play an important role in drag and lift development) could be treated as a porous media (e.g. the radiator, the condenser, air filters, etc). In recent years industries like aerospace and those related to oil production have increased their trustfulness on numerical models and codes for the design, research, production and verification of highly critical parts and production processes. Most of these industries have adopted manufacturing procedures involving composites materials in liquid state, like the Liquid Composite Molding (LCM) and the High Pressure Resin Transfer Molding (HPRTM) methods, where a Newtonian (or Non-Newtonian) fluid flows through highly anisotropic matrices filling an initially empty container. In this article the numerical modeling of the flow through general anisotropic porous media using LS-DYNA is introduced. A generalization of the Navier-Stokes equations that will allow the definition of sub-domains with different permeability/porosity was developed. The SUPG/OSS stabilizing Finite Element Method for the spatial approximation and the second-order Fractional Step Method for the time integration were adopted. Also, the paper will provide some examples showing the use of LS-DYNA in a wide range of low problem.