A CFD analysis of the download reduction for the V-22 Osprey wing

The V-22 tilt rotor aircraft experiences a download in hover mode decreasing the aircraft's efficiency in this mode. This download is caused by the wing surface obstructing the rotor downwash. The presented research, conducted at West Virginia University (WVU) by the Center for Industrial Research Applications (CIRA), explores the reduction of this download via circulation control. Circulation control is implemented through the use of blowing slots at both the leading and trailing edges of the wing. The analysis was completed using computational fluid dynamics.; The Mechanical and Aerospace Engineering department of West Virginia University, in conjunction with The Center for Industrial Research Applications constructed a wind tunnel model of the V-22 wing section, with blowing slots at the leading and trailing edges. The model was tested in the WVU low speed wind tunnel with a free stream velocity of 59 ft/s. This research concluded that a reduction in drag was observed with the use of the blowing slots. A 2-D virtual model was created, mimicking the WVU wind tunnel model, with blowing slots at the leading and trailing edges and a flap angle of 67 degrees. The model was then imported into the commercial CFD preprocessing package GAMBIT for grid generation and boundary condition implementation. The mesh file was then imported into the CFD processing package FLUENT.; The results show that the trend of download reduction via blowing slots is observed in both the wind tunnel experiment and the CFD analysis. Further CFD analysis shows that, although the constraints of the wind tunnel walls and the testing apparatus influence the results, the download reduction remains present in the freestream condition absent of the aforementioned constraints.