The aim of this thesis is to design and manufacture Magnus wind turbines with/without the collecting plate and to determine the Cp versus l characteristic curves. The power of wind turbine is also measured against the wind speed to compare the efficiency of the wind turbines. On this basis, a stationary and a rotating circular cylinder is placed in a cross flow and the corresponding lift and drag forces are calculated. Then, the steady state flowfield around the cylinders are computationally simulated using different turbulence models. However, the nature of the flow was unsteady so that causes unacceptable errors in solution. Next, a transient solution is obtained and with using appropriate turbulence models the more acceptable results are obtained. This is taken as the basis for to analysis the flow around rotating cylinders in presence of the collecting plates with 90 and 135 degrees. The results for these cases then are compared with the rotating cylinder without the plates. Finding the correct angle for the collecting plate, the wind turbine were designed and manufactured. Finally, the performance curves such as power and torque are obtained against wind speed. In fact considering low manufacturing costs of Magnus wind turbines in comparison with the aerofoil type commercial wind turbines, the economic aspects of the new Magnus designs can be evaluated. By varying the rotational velocity of the circular cylinders , as means of the turbine impeller , from 300 rpm to 8000 rpm , the power coefficient are obtained versus the wind turbine tip-speed ratio , and also with the power curve of some other conventional wind turbine. Some correlation is used to relate the rotor rotational velocity to the cylinder rotational speed. from the simulation results , the benefit of using Magneous wind turbine is assessed in comparison with other conventional wind turbine. The thesis comprise five chapters. In the first chapter , the litreture of Magneous type wind turbines are reviewed. In the second chapter , the physical concept of Magneous effect in ideal flows are discussed. In the third chapter , the governing Viscous fluid flow equations are given and the various turbulence models used in this study are explored.In chapter four , the geometry of the problem are introduced and the simulation results are discussed. In the final chapter of 5 , the conclusion of this work and suggestion for future work is given. Key words Magnus wind turbine; spinning cylinder; Magnus force; the collecting plate of 90 and 135 degrees.