An advanced circulation control rotor concept identified as the Reverse Blowing-Circulation Control Rotor (RB-CCR) is discussed from the standpoint of general requirements for high speed flight. This discussion centers on a rotor solidity ratio compromise between hover, transition and cruise requirements. It is shown that the critical solidity requirement occurs in transition where high lift capability is needed while maintaining rotor moment trim. An analytical and experimental investigation of the aerodynamic environment in the transition flight regime (advance ratios of 0.5 to 1.4) indicates that large local yawed flow angles do not severely affect the lift augmentation and maximum lift coefficient of circulation control airfoils. A RB-CCR model was designed and tested at the David W. Taylor Naval Ship Research and Development Center (DTNSRDC). This rotor is unique in its employment of a special circulation control airfoil which has a slot in the leading and trailing edge. The results of several test programs verified the capability of the rotor to perform efficiently in hover and at advance ratios up to 4.0. The model data also demonstrated that the rotor is capable of developing sufficient lift to fly through the critical advance ratio of 0.7.
Circulation Control Applied to a High Speed Helicopter Rotor
1977
22 pages
Report
No indication
English
Aircraft , Helicopter rotors , Trim(Aerodynamics) , Level flight , Ratios , Aerodynamic slots , Aerodynamic characteristics , Airfoils , Circulation , Control , Hovering , Augmentation , Lift , High lift , High velocity , Leading edges , Trailing edges , Coefficients , Moments , Flight envelope , Transitions , Circulation control airfoils , Reverse blowing , RBCCR(Reverse Blowing Circulation Control Rotors) , Transition flight , Solidity ratio , Advance ratio , Lift augmentation
High speed helicopter rotor design
Engineering Index Backfile | 1963
|Designing high-speed rigid rotor helicopter
Engineering Index Backfile | 1963
|