Wind-Tunnel Evaluation of a 21 Percent-Scale Powered Model of a Prototype Advanced Scout Helicopter
Wind-Tunnel Evaluation of a 21 Percent-Scale Powered Model of a Prototype Advanced Scout Helicopter
- New search for: A. E. Phelps
- New search for: J. D. Berry
- New search for: A. E. Phelps
- New search for: J. D. Berry
This exploratory wind-tunnel investigation was conducted in the Langley 4- by 7- Meter Tunnel. The investigation was conducted to define the overall aerodynamic characteristics of the Army Helicopter Improvement Program (AHIP), to determine the effects of the rotor on the aerodynamic characteristics, and to evaluate the effect of a mast-mounted sight on the aircraft stability characteristics. Tests covered a range of thrust coefficients, advance ratios, angles of attack, and angles of sideslip and were run for both rotor-on and rotor-off configurations. Results of the investigation showed that the prototype configuration was longitudinally unstable with angle of attack for all configurations tested. The instability was due to unfavorable interference effects between the horizontal tail and the wake shed from the engine pylon and rotor hub, which caused a loss of horizontal-tail effectiveness. The addition of the mast-mounted sight had little effect on the stability of the model, but it caused an alteration in the rotor lift distribution that resulted in substantial interference drag for the sight.
Document information
Wind-Tunnel Evaluation of a 21 Percent-Scale Powered Model of a Prototype Advanced Scout Helicopter
1985
76 pages
Report
No indication
English
Aircraft , Interference , Helicopter rotors , Wake , Sideslip , Stability , Helicopters , Struts , Aerodynamic stability , Masts , Sights , Scale models , Wind tunnel models , Aerodynamic configurations , Thrust , Rotors , Reconnaissance aircraft , Aerodynamic characteristics , Angle of attack , Angles , Wind tunnel tests , Army aircraft , Engines , Drag , Prototypes , Coefficients , Hubs , Distribution , Lift , Ratios , Test and evaluation , ASH(Advanced Scout Helicopters) , Scout helicopters , AHIP(Army Helicopter Improvement Program) , Mast mounted sights