부산대학교 도서관

In a radial bed, the uniformity of the pressure drop distribution is investigated by Euler single-phase flow and porous media models under different operating mode (CF-U/Z, CP-U/Z), gas flow rate (120-240m3/h), particle diameter ((0.5-3)exp-3 m) and bed voidage (0.3-0.6). According to the nonuniform index η, the uniformity relates to these parameters and improves with increasing total pressure drop of particle bed Δps (sum of the pressure drops of particle bed and gas perforation) or decreasing main channel pressure drop Δpg. Comparing the flow fields with/without particles, Δps is approximately equal to the pressure drop of the particle bed with high-porosity Johnson net, which is well calculated by the Ergun equation. Δpg can be calculated by the modified momentum equation containing k. After changing the wall shear stress and gas-solid axial resistance, it is found that the internal generation factors for k include the influence of gas perforation on boundary layer and the existence of gas axial velocity after perforation. Besides, the global/local k hardly changes with the investigated parameters. The local k is a function of axial position or velocity ratio, which changes obviously at the end of the main channel for the existence of a gas stagnation zone.