This paper presents a study of the wake behavior behind horizontal axis wind turbines (WTs) using CFD. Simulations are carried out to identify the most effective WTs distribution that improves the performance of the wind farm as a whole. The rotors are modeled by using the actuator disk theory and the simulations are performed using ANSYS FLUENT. An assumed land space of 13D width and 20D length is considered for the WTs arrangement, where D is the rotor diameter. Different configurations with different distances between WTs (6D, 8D and 10D) and three prevailing wind directions are considered. Results show that the changes in WTs distribution significantly affect the wind power available in the wind farm. Staggered configuration of 6D separation distance is found to have the best power output, even with less number of WTs. It is also observed that the change in the wind direction blowing to the wind farm can lead to more than 100% change in the power output especially for non-staggered configurations.