Direct numerical simulation of fluid flow accompanied by coupled mass and heat transfer in dense fluid-particle systems

In this paper we report the extension of an earlier reported DNS method (Deen et al., 2012 and Deen and Kuipers, 2013) based on a novel Immersed Boundary Method (IBM) which incorporates the fluid–solid coupling at the level of the discrete field equations. The extended method is used to study coupled mass and heat transport in dense fluid–particle systems where the coupling arises as a consequence of an exothermal chemical reaction proceeding at the exterior surface of the particles. Following a detailed verification (using an independent numerical technique) and validation (using established empirical correlations) we apply our DNS technique to study coupled mass and heat transfer in a dense fluid–particle system. In addition a comparison is made with results obtained from a simple one-dimensional (1D) heterogeneous reactor model which uses empirical closures for the fluid–particle mass and heat transfer coefficients. The main features of the complex transient temperature profiles obtained from our DNS agree quite well with the corresponding profiles obtained from the 1D heterogeneous reactor model.