In this baccalareus graduate thesis geometry modifications of pump parts which affect working fluid flow are made. Those modifications improved the flow pattern and therefore recirculation flow areas were minimized. Friction pump geometry is modified using a commercial solid modelling computer-aided design (CAD) and computer-aided engineering (CAE) computer program SOLIDWORKS. Friction pump geometry is simplified by following conclusions from the past research. Several geometry modifications are made. There are two main design solutions. First design solution is purposed for higher volume rate operating range. The second design solution is purposed for wider volume rate operating range. Second design solution is adopted. In this thesis design stages are attached. Geometry modifications, mesh discretization of a domain and streamlines are also attached in every design stage. After the first construction design, comparison between computer simulation results and the approximate analytical solution is made taking the increase in pressure as a main parameter. Difference between them is analyzed. Fields of wall shear stress and shear stress in the power of the working fluid which has no contact with the walls of the operating point of the pump which benefits a man suffering from hypertension are attached. The comparison with the subjects from the previous work is reflected here. At the end of this thesis, two pump characteristic curves Q-Δp (for the same shaft rotational speed but different volume flow rate) and pressure increase - shaft rotation speed Δp-n (for the constant volume flow rate) are attached. Domain is discretized using a SALOME platform. Numerical calculations of steady-state flow is performed using OpenFOAM, software tool for computional fluid dynamics.