The lack of constitutive drag laws for non-spherical particles represents a current gap in simulating fluid-particle flows, even though such non-spherical shapes are encountered in numerous applications. Some previous studies have applied spherical drag models to non-spherical particles, while others have used ad-hoc methods to account for particle shapes. However, the present work demonstrates the need to develop dedicated non-spherical drag laws, given the limitations of these previous ad-hoc approaches. In the present study, single-phase computational fluid dynamics (CFD) simulations of fluid flow over random arrays of ellipsoids are used to directly calculate the fluid-particle drag forces. By varying the particle shape, orientation, solid fraction, and fluid-flow velocity (Reynolds number), this work probes the variables that would be important for future model development. A preliminary non-spherical drag model is proposed based on the CFD results, which illustrates the functional dependency of the non-spherical drag on particle aspect ratio and orientation.

缺乏非球形颗粒的本构阻力定律表示了模拟流体颗粒流动的当前间隙，即使在许多应用中遇到了这种非球形形状也是如此。先前的一些研究已将球形阻力模型应用于非球形粒子，而其他研究则使用了临时方法来解释粒子形状。但是，鉴于这些以前的临时方法的局限性，当前的工作表明需要开发专用的非球形阻力定律。在本研究中，通过椭圆体的随机阵列上的流体流动的单相计算流体动力学（CFD）模拟用于直接计算流体颗粒的阻力。通过改变颗粒的形状，方向，固体分数和流体流动速度（雷诺数），这项工作探讨了对将来的模型开发很重要的变量。基于CFD结果，提出了初步的非球形阻力模型，该模型说明了非球形阻力对颗粒长宽比和取向的功能依赖性。