A shrouded wind turbine comprises a shroud disposed about an impeller. The impeller surrounds a nacelle body which is shaped to enhance smooth flow of wind through the impeller. Some embodiments include an inlet and an outlet in the nacelle body, allowing airflow through an interior cavity. Other nacelle bodies may be tapered, flared, include mixing lobes around a trailing edge, or may have other shapes that enhance fluid flow. Some nacelle bodies include an annular groove that promotes flow attachment. Maintaining airflow attachment to the nacelle body within the turbine increases the energy generation capacity of the wind turbine.