致密气体流化床的实验和直接数值模拟研究

We report our study on fluidization of 5000 spherical particles in a pseudo-2D gas-fluidized bed by direct numerical simulations (DNS) and experiments as well. DNS are performed using an immersed boundary method, together with the methodology developed in our earlier work for accurate prediction of gas-solid interactions at relatively low grid resolutions. Experimental measurements of solids mean motion are conducted using a combined particle image velocimetry (PIV) and digital image analysis (DIA) technique. Furthermore, the PIV technique is extended and applied for instantaneous measurements of the particle granular temperature, which is a key characteristic of particle velocity fluctuations. This paper presents a detailed direct comparison between IBM simulation results and experimental data for realistic gas fluidization, which has not been reported before in literature. The comparison reveals a good agreement with respect to the time-averaged solids motion, as well as the fluctuations of the pressure drop over the bed. The granular temperatures calculated from the simulations also agree very well with the experimental data measured by the extended PIV technique.