Flow-Controlled Inflatable Fairings for Helicopter Hub Drag Reduction

Techsburg, Inc. proposes to perform experimental proof-of-concept testing of a flow-controlled inflatable fairing concept for helicopter hub/shaft drag reduction. The proposed system includes a rigid hub fairing coupled with an inflatable shaft fairing. Flow control jets emit from the shaft fairing and produce an aerodynamic seal between the hub and shaft fairings, utilizing the Coanda Effect to convert the jet momentum to aerodynamic lift on the hub fairing. During Phase I, a subscale helicopter fuselage model employing the proposed drag reduction technology will be tested in a continuous, subsonic wind tunnel with a 6 ft by 6 ft test section. The drag reduction due to the proposed system will be quantified in the wind tunnel tests, and the concept will be further optimized using both computational fluid dynamics and further experiments in Phase II.