Summary: In single screw plasticizing technology dispersive mixing elements, i.e., axial and spiral Maddock shear heads, are often used to improve the melt quality. Mathematical models are necessary to efficiently design the mixing section. An analytical model for the design of Maddock mixers is presented in this work. In addition, a CFD-software package is employed to determine the flow and pressure field for different geometries and processing conditions. For the design and process analysis of fluted dispersive mixers the validity and potential of simplified analytical solutions are compared to more versatile and detailed CFD-simulations.