Comparing Numerical and Experimental Results for Drag Reduction by Active Flow Control Applied to a Generic Rotorcraft Fuselage

Helicopter fuselage drag reduction using active flow control is a topic that has been addressed both by NASA and ONERA over recent years. Some common investigations were performed under the framework of the US/France Memorandum of Agreement on Helicopter Aeromechanics with both entities conducting independent research on generic rotorcraft fuselages. In particular, the ONERA ASF2 fuselage has undergone a comprehensive experimental study, with two successive wind-tunnel campaigns, that has resulted in a large experimental database. The experimental work demonstrated significant drag reduction over a wide range of angles of attack was possible through the use of two different flow control strategies. A portion of this experimental database was used in a collaborative investigation between ONERA and NASA to evaluative the effectiveness of Reynolds-Averaged Navier-Stokes solvers to predict these types of flows. This investigation demonstrates that the NASA and ONERA flow solver codes were able to predict the major trends observed in the experiment, however they were not able to quantitatively predict the fuselage forces or performance of the flow control.