The paper investigates the flow behavior near the NACA 64-618 airfoil profile of the blade tip section of a wind turbine for electric power production after a short icing event. The flow simulation considering the rotation speed of the wind turbine blade is performed to assess the effect of icing on the aerodynamic characteristics. Degradation of aerodynamic characteristics affects the electrical energy production of the wind turbine. The aerodynamic lift and drag coefficients are calculated for different angles of attack. The flow velocity fields near the airfoil are analyzed. The pressure coefficient distributions along the profile surface are obtained. The points of flow stall and changes of aerodynamic characteristics at different angles of attack are determined.

The paper considers the details of design and construction of a small-sized wind tunnel with an open circuit and a closed test section for investigating the blades of horizontal-axis wind turbines. The effect of different types of jet straighteners on the turbulence of the flow in the test section has been studied. Turbulence flow distributions Tu at Reynolds numbers Re from 5·103 to 2·104 are obtained using Laser Doppler Anemometry methods. As a result, the wind tunnel design with average flow turbulence of 1.6 % is obtained. The flow visualization of NACA 64-618 airfoil at Re = 5·103 is obtained.