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The wind passing through upstream wind turbines becomes slower and more turbulent.This is known as the wake.The wake reduces the annual energy production and increases the dynamic loads of the wind turbines in the downstream of a wind farm.The objective of this study was to develop an in-house code to predict the wake field of an offshore wind farm.For this,an in-house code consisting of a two-dimensional model for turbulent wind field generation,a wake model based on the eddy viscosity turbulence closure,an effective turbulence model in the downstream of wind turbines and the NREL 5 MW wind turbine model was developed.The simulation results with the simulation model mostly underpredict the actual power output when the wind direction is close to 0°.This means that the eddy viscosity wake model used in the simulation overpredicts the velocity deficit in the wake field.The reason for the change in discrepancy with wind direction is considered to be due to meandering,which is the fluctuation of wake center.To consider the meandering effect in the wake model,a compensation factor was introduced.From the comparison it was found that the eddy-viscosity wake model with the effective turbulence model overpredicted the wake field and finally underpredicted the electrical power specially when the wind turbines are in line with the wind direction.The eddy viscosity model with the compensation factor was found to be better estimate the wind farm power output,but further analysis on the factor is needed.