Influence of inlet boundary condition on flow field of bubbling fluidized bed with orifice near the wall

In order to study the influence of velocity inlet boundary condition on the bubble behavior in a bubbling fluidized bed with orifice near the wall, numerical simulation has been performed to the gas-solid two-phase flow in the bed using Euler-Euler two-fluid model and standard k~ε equation under steady velocity inlet boundary conditions as well as turbulent velocity inlet boundary conditions respectively with normal and SIN distribution items. Results show that under turbulent inlet boundary conditions, bubbles may form in other areas except for the orifice, and the rising speed of bubbles will be slower than that under steady conditions. Under turbulent conditions, the gas mixes with solid particles adequately, and the dominant frequency of voidage signals is relatively smaller. For reasonable prediction of the bubble size and velocity, it is recommended to consider the turbulent factors when setting relevant boundary conditions.