In recent years, public concern about environmental affair is growing at the same time, wind power generation systems have been common, it is required to improve the efficiency of wind turbine blades, leading to its operational stability and high efficiency. In this study, it is examined if the blade surface roughness affects the flow condition around the wind turbine blades to control the blade performance. Specifically, the flow velocity around blades are measured by using the hot-wire anemometer, so as to identify the flow behavior on the blade surface and behind the blades. As a result, flow separation is decreased because of contain roughness on the blade, and it is clarified that flow behavior on the blade surface and behind the blades is changed due to the blade surface roughness.
