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

•Hexagonal and square lattices under steady-state, fully developed conditions.•Axial flow: fz and Sh increase by 26% and 79% in the hexagonal lattice.•Transverse flow: fT increases by 10-36% in the hexagonal lattice; similar Sh values.•Mixed flow: fT unaffected by axial flow; fz increased at transverse Re>~5-10.•Sh is the larger between that of purely transverse flow and purely axial flow.