Heat transfer by conduction using DEM–FEM coupling method

Abstract

The mechanical and physical behaviors of complex systems are generally predicted by using the Finite Element Method (FEM). However, the treatment by FEM of non-linear material behavior and heterogeneous media is not straightforward. Conversely, the Discrete Element Method (DEM) is most suitable for modeling discontinuities and microscopic phenomena. But, in some cases such as the modeling of large structures, the DEM may lead to very costly computational time.To provide a realistic simulation for complex systems requires a modeling describing physical phenomena and structure heterogeneities with a good accuracy and an acceptable computational time. This paper deals with the modeling of heat transfer in 2D continuous medium using cylindric discrete elements and the DEM–FEM coupling method applied to heat transfer in structures presenting an overlapping zone to ensure continuity between continuous and discrete domains. Therefore, the proposed modeling enables us to benefit from both DEM and FEM and will also be useful in many practical applications.A simple test performed on a flat plate submitted to thermal boundary conditions with a known analytic solution allowed us to validate the discrete model for heat transfer. Furthermore, comparisons between numerical results obtained with the DEM, FEM and DEM–FEM coupling method have been carried out through simulations of heat transfer. These comparisons show a good agreement between numerical results and validate the DEM–FEM coupling method for heat transfer.