The purpose of this study is to investigate the effects of the size and location of wind fences on the rotor performance to avoid as well as quantify any adverse effects of outside wind on the measurement accuracy. To this end, firstly, a novel actuator disk method is developed which couples open source CFD code named OpenFOAM with blade element method and rotor flapping equations. Secondly, the parametric studies are conducted with respect to wind fence configurations which contain fence radius, inlet/outlet duct size and location etc. For quantitative evaluation of rotor performance variation according to inlet/outlet duct size, the mass flow and momentum rate on the ducts are. The rotor performance variation depending on the wind fence configuration is examined and consequently parametric study cases are classified according as calculated rotor thrust coefficient. Moreover, it is explained the difference of flow field in wind fence by demonstrating the pressure coefficient. Finally, some optimal wind fence configurations are suggested which minimizes the aerodynamic interference effects with the rotor.