The capillary membrane technology has become one of the effective methods for producing drinking water. The membrane lifetime and permeability are significantly affected by operating and backwash conditions. To enhance the backwash process, the flow in the porous wall and the pressure drop inside the capillary membrane were investigated numerically. For this purpose, 3D model describing steady-state laminar flow inside the capillary membrane operated in dead-end mode was simulated. The influence of various boundary conditions on both the flow pattern inside the capillary membrane and the characteristic of the membrane were studied. Hereby, the pressure drop in the module and the axial as well as radial velocity profile were estimated with the consideration of the membrane fouling. The calculation of permeate flux contributes to increase the backwash performance and minimize energy consumption. The method of coupling Navier-Stokes equation for the free flow and Darcy-Forchheimer approach for the prediction of the flow in the porous membrane is proposed in the current study. The CFD model was validated by comparing the numerical results with the experimental data. A very good agreement was achieved.