Simulation on flow behavior of particles and its effect on heat transfer in porous media

Mastering flow and heat transfer of fluids in porous media is significant in the development of oilfield. A three-dimensional porous model with anisotropic pore structure is developed, and flow and heat transfer behaviors of particles are simulated using CFD-DEM method incorporating with the coupled convective-conductive heat flow model. The interphase forces including drag force, lubricating force and thermophoretic force are considered comprehensively. Comparisons of the predicted results are also made and in a good agreement with the classical experimental results by Rimon. Simulation results show that the temperature in porous media rises along with the mixing and contact between particles and liquid. The migration of moving particles is restricted in pore spacing, and thus narrows the apertures of fluid channel, increases the local instantaneous liquid velocity. Moving particles are preferred to decelerate and deposit at a low porosity. The velocities of particles and frequency of collision increase while contact force and granular temperature decrease with an increase of porosity. With the increase of particle temperature, the temperature gradient around hot particles enlarges and the number of trapped particles goes up affected by thermophoretic force. The intensity of convection heat decreases at lower liquid velocity, and the heat conduction between particles is regarded as the main heat transfer mechanism.