CFD prediction of shell-side flow and mass transfer in regular fiber arrays

摘要

Numerical simulations were conducted for fully developed, steady-state flow with mass transfer in fiber bundles arranged in regular lattices. The porosity was 0.5 and the Schmidt number 500. Several combinations of axial flow, transverse flow and flow attack angles in the cross-section plane were considered. The axial and transverse Reynolds numbers Re_z, Re_T were made to vary from 10~(-4) to 10~2. Concentration boundary conditions, and the definition of an average Sherwood number, were addressed. Results for the hydraulic permeability were compared with the literature. Both hexagonal and square lattices were found to be hydraulically almost isotropic up to transverse flow Reynolds numbers Re_T of ～10, while they behaved anisotropically in regard to mass transfer even at Re_T as low as 0.1. A larger anisotropy was exhibited by the square lattice. In mixed (axial+transverse) flow, the transverse friction coefficient was almost completely unaffected by the simultaneous presence of axial flow, while the axial friction coefficient (and thus the axial pressure loss) increased with the transverse Reynolds number for Re_T＞～5-10. In regard to mass transfer, the Sherwood number settled in all cases to the higher between the Sherwood number in purely transverse flow and that in purely axial flow.