Sound waves in fluidized bed using CFD–DEM simulations

Abstract

The speed of sound waves is investigated using CFD-DEM numerical simulations. Appropriate initial and boundary conditions are applied to capture the phenomenon. The effect of varying the height of the bed is also studied. The results of the simulations matched those from literature. The pressure and particle velocity profiles from the simulation showed the oscillatory behavior. Functions (based on a damped standing wave) were fitted to these, which allowed them to be stated in time and space variables. These fitted functions were substituted to the linearized governing equations for the two-phase flow. Using these assumed solutions allowed a new relationship to be derived for the speed of sound and damping in the system. It is concluded that the damping in the system is due to the effective bulk viscosity of the solid phase, which arises from the particle viscosity.