Conduction, convection, and radiation thermal exchange with discretized fixed, contacting particles in a high speed compressible flow

Abstract

A novel technique is proposed to simulate the thermal interactions occurring within a compressible fluid flow with particles. Thermal exchanges between particles, fluid, and flow paths including particle-particle and particle-solid body contact are included. Contact conduction with a contact resistance, convection, and radiation modes of heat transfer are accounted for without the need for heat transfer coefficient correlations or other simplifying assumptions since the particles are discretized within the fluid domain. The discretization of the particles in the flow allows for the local temperature and flow field data to be utilized in calculating the thermal interactions and facilitates the exploration of temperature dependent phenomena based on local instead of bulk interface conditions. So that these developed techniques can be applied to computational fluid dynamics simulations with moving objects, a fluid gap space is retained around the particles while the thermal conductive contact effects are simulated. The method is applied to an eleven fixed particle configuration with the flow driver strengths and limited radiative emissivities varied. The results demonstrate that for the conditions considered, the conductive contact dominates the temperature field development, with the radiative and convective cooling taking a lesser role. The new method clearly improves capabilities for the study of the thermal interaction in particle laden high speed gas flow and thus of temperature dependent phenomena for a more comprehensive simulation.