The particle stress tensor is an indispensable part of continuum theory for gas–solid flow. In this study, computational fluid dynamics–discrete element method (CFD–DEM) simulations were performed to extract the particle stress tensor in gas-fluidized beds. It was shown that the numerically extracted particle pressures exerted on the wall are in excellent agreement with the experimental data available in the literature, thus offering a direct experimental validation of the approach that extracts the particle stress tensor using the CFD–DEM method. Furthermore, it was found that (i) bubble motion is the main source of generating particle stress, (ii) the size of the transducer has no effect on the measured particle stress on the wall, (iii) the particle pressure is approximately isotropic, and (iv) the particle stress on the wall differs significantly from that inside the bed. The present study proved that the CFD–DEM method is a powerful tool to explore the physical nature of particle phase stress.

中文翻译：

---

气体流化床中的粒子压力：计算流体动力学-离散元方法研究

粒子应力张量是气固流动连续介质理论中不可或缺的一部分。在这项研究中，进行了计算流体动力学-离散元法 (CFD-DEM) 模拟，以提取气体流化床中的粒子应力张量。结果表明，数值提取的施加在壁上的粒子压力与文献中可用的实验数据非常一致，从而为使用 CFD-DEM 方法提取粒子应力张量的方法提供了直接的实验验证。此外，发现（i）气泡运动是产生粒子应力的主要来源，（ii）换能器的尺寸对壁上测量的粒子应力没有影响，（iii）粒子压力近似各向同性，(iv) 壁上的颗粒应力与床内的显着不同。本研究证明，CFD-DEM 方法是探索颗粒相应力物理性质的有力工具。