TY - JOUR
T1 - Full-scale flight tests of active flow control to reduce Tiltrotor aircraft download
AU - McVeigh, Michael A.
AU - Nagib, Hassan
AU - Wood, Tom
AU - Wygnanski, Israel
N1 - Funding Information:
Three universities (University of Arizona, Tel Aviv University, and Illinois Institute of Technology) and two major aerospace companies (The Boeing Company and Bell Helicopter Textron, Inc.) were involved in this project, which was administered by the U.S. Army Research Office under contract number DAAD19-99-C-0023. Many people contributed to this program, which lasted over 4.5 years. The authors wish to acknowledge the assistance of J. McMichael, R. Wlezien, and S. Walker of the Defense Advanced Research Projects Agency, who steered this project to its successful conclusion. There were many technical contributors to this program whose names do not appear in the list of authors. Aerodynamic testing and computation were made by N. Anderberg, D. Cerchie, L. Cullen, A. Darabi, D. Greenblatt, R. Grife, A. Hassan, J. Kiedaisch, P. Kjellgren, M. Schmalzel, and A. Stalker. Special thanks are due to D. Hodder for his design of the hover rig and the rigorous calibration effort. The support of the Bell Helicopter Flight Test Team is greatly appreciated.
PY - 2011
Y1 - 2011
N2 - The vertical force, or download, acting on the airframe of current tiltrotor configurations during hover amounts to approximately 10% of rotor thrust, or about 6000 lb for the V-22. Various mechanical means have been experimentally tried to reduce this penalty, but none has been implemented, largely because of mechanical complexity. This paper describes the research conducted on the application of active flow control to the problem, since this technique may offer a solution without large weight penalties and unacceptable complexity. The research was conducted as part of the Defense Advanced Research Projects Agency Micro Adaptive Flow Control program. The work culminated in June 2003, when the NASA/U.S. Army/Bell XV-15 tiltrotor aircraft was used to successfully demonstrate the effectiveness of active flow control in reducing airframe download during hover. The wing flaps were fitted with zero-mass-flow actuators that periodically injected/removed air in the flap upper surface boundary layer through slots from the interior of the flap. The active flow control was effective in delaying flow separation from the flap, which reduced the download on the wings. The flight tests were the culmination of extensive laboratory experiments on two-dimensional models and on a powered full-span 16%-scale model of the XV-15 aircraft. The XV-15 flight tests confirmed the laboratory findings by successfully reducing the download measured in hover by as much as 14%, demonstrating that the aerodynamic principles of active flow control can be applied to full-scale air vehicles.
AB - The vertical force, or download, acting on the airframe of current tiltrotor configurations during hover amounts to approximately 10% of rotor thrust, or about 6000 lb for the V-22. Various mechanical means have been experimentally tried to reduce this penalty, but none has been implemented, largely because of mechanical complexity. This paper describes the research conducted on the application of active flow control to the problem, since this technique may offer a solution without large weight penalties and unacceptable complexity. The research was conducted as part of the Defense Advanced Research Projects Agency Micro Adaptive Flow Control program. The work culminated in June 2003, when the NASA/U.S. Army/Bell XV-15 tiltrotor aircraft was used to successfully demonstrate the effectiveness of active flow control in reducing airframe download during hover. The wing flaps were fitted with zero-mass-flow actuators that periodically injected/removed air in the flap upper surface boundary layer through slots from the interior of the flap. The active flow control was effective in delaying flow separation from the flap, which reduced the download on the wings. The flight tests were the culmination of extensive laboratory experiments on two-dimensional models and on a powered full-span 16%-scale model of the XV-15 aircraft. The XV-15 flight tests confirmed the laboratory findings by successfully reducing the download measured in hover by as much as 14%, demonstrating that the aerodynamic principles of active flow control can be applied to full-scale air vehicles.
UR - http://www.scopus.com/inward/record.url?scp=79957935485&partnerID=8YFLogxK
U2 - 10.2514/1.46956
DO - 10.2514/1.46956
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AN - SCOPUS:79957935485
SN - 0021-8669
VL - 48
SP - 786
EP - 796
JO - Journal of Aircraft
JF - Journal of Aircraft
IS - 3
ER -