Patent ID: 8419373

Claim:
A wind turbine blade comprising: a blade tip part; a blade root part which is connected to a hub of a wind turbine; and an airfoil part which is disposed between the blade tip part and the blade root part and which includes a flatback airfoil with a blunt trailing edge at least in an area in a longitudinal direction of the wind turbine blade where a blade thickness ratio X is not less than 40% and not greater than 50%, X indicating a ratio of a maximum thickness t MAX to a chord length L C , wherein, in the area where the blade thickness ratio X is not less than 40% and not greater than 50%, the flatback airfoil has a trailing edge thickness ratio Y which is not less than 5% and not greater than Y H %, Y indicating a ratio of a trailing edge thickness t TE to the maximum thickness t MAX , and wherein Y H has a relationship of Y H =1.5X−30 with the blade thickness ratio X.