Numerical investigation on the effect of the incident angle on momentum and heat transfer of spheroids in supercritical water

This paper studies the effect of the incident angle (theta) on momentum and heat transfer of spheroids in supercritical water (SCW) based on numerical simulations. Both prolate and oblate spheroids are considered with the aspect ratio (Ar) ranging from 0.5 to 2.5. Numerical results show that both the drag coefficient (Cd) and average Nusselt number (Nu) of the oblate spheroid (Ar < 1) in SCW decrease with the increase of theta. Opposite trend is found for the prolate spheroid (Ar > 1). When theta <= 45 degrees, both Cd and Nu of the two kinds of spheroids decrease with the increase of Ar. When theta > 45 degrees, both Cd and Nu of the prolate spheroid increases with Ar. Nu of the oblate spheroid also increases with Ar but its Cd is dependent on the competition of friction and pressure. The effect of theta on Nu can be enhanced by either lifting Re or vertical bar Ar-1 vertical bar. At last, the effect of theta is directly considered in the correlations of Cd and Nu for spheroids in SCW which can improve the accuracy of the multi-phase flow modellings of SCW. (C) 2018 Elsevier Ltd. All rights reserved.