Particle-resolved simulation on viscous flow past random and ordered arrays of hot ellipsoidal particles

Abstract

Particle-resolved simulation is performed to study the drag force on arrays of ellipsoidal particles with a temperature difference with respect to the surrounding fluid. The effect of particle shape, arrangement, solid volume fraction and particle temperature is examined. We found that the particle shape and arrangement strongly influence the drag coefficient CD when the particle volume fraction ϕ is small. The influence, however, is inhibited as ϕ increases. We also show that the drag coefficient decreases with the increase of the solid volume fraction, which is a reversal of the trend found in previous uniform suspension systems. Moreover, CD increases with the increase of particle temperature while slightly decreases with the fluid temperature. Through a novel decomposition analysis, we show that the increase of fluid viscosity causes the increase of CD when the particle temperature is increased, while a combined effect of the fluid density, inlet velocity and the integral of the velocity gradient around particle on CD was observed when the fluid temperature changes. Finally, new drag correlations, as power functions of Reynolds number, particle temperature and volume fraction, are proposed for clusters with different particle shapes and arrangements.