A shrouded fluid turbine includes a ringed airfoil having a leading edge, a trailing edge, an outer surface, an inner surface, and a body extending from the leading edge to the trailing edge. The shrouded turbine further includes a rotor surrounded by the ringed airfoil. The rotor is disposed downstream of the leading edge and about a central axis of the fluid turbine. The shrouded turbine further includes an aperture extending through the body of the ringed airfoil between the outer surface and the inner surface. The aperture is configured to mix a first fluid flow adjacent to the outer surface of the ringed airfoil and a second fluid flow downstream of the rotor.