Circulation Control Technology Applied to Propulsive High Lift Systems

1984 ◽  
Author(s):  
Robert J. Englar ◽  
James H. Nichols ◽  
Michael J. Harris ◽  
Joseph C. Eppel ◽  
Michael D. Shovlin
Keyword(s):  
Control Technology ◽  
Circulation Control ◽  
High Lift

Circulation Control Span-Wise Blowing Location Optimization for a Helicopter Rotor Blade

2010 ◽  
Author(s):  
Alan M. Didion ◽  
Jonathan Kweder ◽  
Mary Ann Clarke ◽  
James E. Smith
Keyword(s):  
Stress Reduction ◽  
Rotor Blades ◽  
Helicopter Rotor ◽  
Base Line ◽  
Control Technology ◽  
Circulation Control ◽  
High Lift ◽  
Location Optimization ◽  
Helicopter Rotor Blades ◽  
Length Reduction

Circulation control technology has proven itself useful in the area of short take-off and landing (STOL) fixed wing aircraft by decreasing landing and takeoff distances, increasing maneuverability and lift at lower speeds. The application of circulation control technology to vertical take-off and landing (VTOL) rotorcraft could also prove quite beneficial. Successful adaptation to helicopter rotor blades is currently believed to yield benefits such as increased lift, increased payload capacity, increased maneuverability, reduction in rotor diameter and a reduction in noise. Above all, the addition of circulation control to rotorcraft as controlled by an on-board computer could provide the helicopter with pitch control as well as compensate for asymmetrical lift profiles from forward flight without need for a swashplate. There are an infinite number of blowing slot configurations, each with separate benefits and drawbacks. This study has identified three specific types of these configurations. The high lift configuration would be beneficial in instances where such power is needed for crew and cargo, little stress reduction is offered over the base line configuration. The stress reduction configuration on the other hand, however, offers little extra lift but much in the way of increased rotor lifespan and shorter rotor length. Finally, the middle balanced configuration offers a middle ground between the two extremes. With this configuration, the helicopter benefits in all categories of lift, stress reduction and blade length reduction.

Roll aerodynamic characteristics study of an unmanned aerial vehicle based on circulation control technology

2017 ◽  
Vol 233 (3) ◽  
pp. 871-882
Author(s):  
Kun Chen ◽  
Zhiwei Shi ◽  
Jiachen Zhu ◽  
Haiyang Wang ◽  
Junquan Fu
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Flight Control ◽  
Attitude Control ◽  
Aerodynamic Force ◽  
Flight Test ◽  
Scale Model ◽  
Maximum Efficiency ◽  
Control Technology ◽  
Circulation Control ◽  
Aerial Vehicle

To explore the control efficiency of circulation flow control technology, a circulation control actuator with an independent gas source has been designed and applied in roll attitude control of a small unmanned aerial vehicle. The circulation control devices are arranged at the two ends of the wing on an unmanned aerial vehicle scale model, the changes in aerodynamic force and aerodynamic moment caused by turning on the actuator are measured in a wind tunnel, and the flow field characteristics are analysed using particle image velocimetry technology. The flight control effect of the roll attitude is verified via a flight test. Experimental and flight test results show that the control of roll attitude can be achieved by turning on the circulation control actuator on one side, and the maximum efficiency that the circulation control generates is equivalent to 8° aileron deflection with production of a favorable yaw moment to achieve a coordinated turn. The circulation control actuator can increase lift and reduce drag when opened on both sides simultaneously. The maximum lift-to-drag ratio of the UAV increased from 5 to 9, and this approach can also suppress flow separation and delay stall at high angles of attack. The aileron or trailing edge flaps can be replaced with circulation control actuators, and the circulation control technology can also be applied to aerodynamic performance improvement and flight control in other types of aircraft.

High Lift Circulation Controlled Helicopter Blade

2006 ◽  
Author(s):  
Gerald M. Angle ◽  
Wade W. Huebsch ◽  
Zenovy S. Wowczuk ◽  
Jacky C. Prucz ◽  
James E. Smith
Keyword(s):  
Wind Tunnel ◽  
Lift Coefficient ◽  
Fold Increase ◽  
General Aviation ◽  
Circulation Control ◽  
Main Rotor ◽  
High Lift ◽  
Helicopter Blade ◽  
Drag Forces ◽  
Lift Capacity

Circulation control techniques have a long history of applications to fixed wing aircraft. General aviation has used circulation control to delay flow separation and increase the maximum lift coefficient achievable with a given airfoil. These techniques have been gradually expanded to other applications, such as ground vehicles, to reduce drag. Circulation control technology can, potentially, be applied also to each blade of the main rotor in a helicopter, in order to increase the lift capacity of the rotor. Applications of circulation control technologies to fixed wing aircraft have demonstrated the potential of a three-fold increase in the lift coefficient, as compared to a conventional airfoil. This finding would suggest that a rotorcraft equipped with circulation control of the main rotor blades could, conceivably, lift up a payload that is approximately three times heavier than the maximum lift capacity of the same helicopter without circulation control. Alternatively, circulation control could reduce the required rotor diameter by up to 48%, if the maximum lift capacity remains unaltered. A High Lift, Circulation Controlled Helicopter Blade will be undergoing initial testing in the subsonic wind tunnel facility at West Virginia University. Two-dimensional elliptic airfoil models with air blowing slots for circulation control will be used as specimens in these tests in order to determine the aerodynamic changes, especially in lift and drag forces, achievable with various blowing slot configurations. Based on the results of the wind tunnel testing, an improved, detailed design will be developed for the entire main rotor of a helicopter with circulation control.

Numerical Simulation of Powered High-Lift Flow

2014 ◽  
Vol 1016 ◽  
pp. 501-505
Author(s):  
Zhi Bin Gong ◽  
Jie Li ◽  
Bin Tian
Keyword(s):  
Numerical Simulation ◽  
Point Of View ◽  
Circulation Control ◽  
High Lift ◽  
The Past

To achieve short-take-off-and-landing (STOL) performance, numerous airframe/propulsion integration (API) technologies have been developed for military and commercial transports. Powered lift technology refers to a concept of utilizing the propulsion exhaust flows to increase lift through an increase in wing circulation []. Over the past seventy years, various concepts have been explored to accomplish this goal. From the point of view of technical characteristics, powered lift concepts can be sorted into three groups: a circulation control wing, blown flaps, and jet wing. Most of other concepts are slight deviations of these three.

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