The speed of sound waves in a fluidized bed is investigated using CFD–DEM numerical simulations. Appropriate initial and boundary conditions are applied to reproduce bed phenomena. The effect of varying the height of the bed is also studied. The results of the simulations matched those from the literature. The pressure and particle velocity profiles obtained feature oscillatory behavior to which functions (based on a damped standing wave) were fitted, enabling an explicit dependence on time and space variables to be established. These fitted functions were substituted into the linearized governing equations for the two-phase flow. These solutions enabled a new relationship to be derived for the speed of sound and damping in the system. The conclusion drawn is that the damping in the system is governed by the effective bulk viscosity of the solid phase, which arises from the particle viscosity.

使用CFD–DEM数值模拟研究了流化床中声波的速度。适当的初始条件和边界条件适用于重现床层现象。还研究了改变床高的影响。仿真结果与文献中的结果相符。所获得的压力和粒子速度曲线具有振荡行为，该函数具有拟合的功能（基于阻尼驻波），从而可以明确依赖于时间和空间变量。将这些拟合函数代入两相流的线性化控制方程式中。这些解决方案为系统中的声音和阻尼速度推导了新的关系。