This study focuses on the combined effect of particle shape and porosity on the momentum and heat transfer of granular matter under laminar flow. Particle-resolved direct numerical simulations (PR-DNS) are carried out at different working conditions. Numerical results show that both the particle shape (via the aspect ratio, Ar, of the spheroid) and porosity play important roles in affecting the drag coefficient (Cd) and average Nusselt number (Nu). The influence of particle shape on Cd and Nu is regardless of the particle porosity. It is found that the Cd decreases with the increase of Ar for a given Reynolds number (Re). The Nu decreases with the increase of Ar under high Reynolds number (100<Re<200), but increases first and then decreases under low Reynolds number (20<Re<100). The influence of particle porosity also highly depends on Re.Under high Reynolds number (100<Re<200), the strong influence of particle porosity on Cd and Nu is mainly caused by the increase of convectional capability of the fluid with Re which can flow into the pore structure easier. On the contrary, the effect of the particle porosity can be almost ignored under low Reynolds number (20<Re<100). Finally, superior to previously available correlations of Cd and Nu for non-spherical solid particles in fluids, the effect of the porosity is considered and novel correlations are established. The high predictive accuracy strongly demonstrates their capability.

本研究侧重于颗粒形状和孔隙度对层流下颗粒物质动量和传热的综合影响。粒子分辨直接数值模拟 (PR-DNS) 在不同的工作条件下进行。数值结果表明，颗粒形状（通过球体的纵横比Ar）和孔隙率在影响阻力系数 ( Cd ) 和平均努塞尔数 ( Nu ) 方面起着重要作用。颗粒形状对Cd和Nu的影响与颗粒孔隙率无关。发现对于给定的雷诺数 ( Re ) ，Cd随着Ar的增加而减少。这Nu在高雷诺数(100< Re <200)下随着Ar的增加而减小，但在低雷诺数(20< Re <100)下先增加后减小。颗粒孔隙度的影响也高度依赖于Re。在高雷诺数下（100< Re <200），颗粒孔隙度对Cd和Nu的强烈影响主要是由于含Re的流体对流能力的增加，可流动更容易进入孔隙结构。相反，在低雷诺数（20< Re<100）。最后，优于先前可用的流体中非球形固体颗粒的Cd和Nu相关性，考虑了孔隙率的影响并建立了新的相关性。高预测准确性有力地证明了他们的能力。