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Effect of active Gurney flaps on overall helicopter flight envelope

Published online by Cambridge University Press:  07 June 2016

V.A. Pastrikakis ,
R. Steijl  and
G.N. Barakos
V.A. Pastrikakis*
Affiliation:
School of Engineering, University of Liverpool, Liverpool, UK
R. Steijl*
Affiliation:
CFD Laboratory, School of Engineering, University of Glasgow, Glasgow, UK
G.N. Barakos*
Affiliation:
CFD Laboratory, School of Engineering, University of Glasgow, Glasgow, UK
*
[email protected]
[email protected]
[email protected]
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Abstract

This paper presents a study of the W3-Sokol main rotor equipped with Gurney flaps. The effect of the active Gurney is tested at low and high forward flight speeds to draw conclusions about the potential enhancement of the rotorcraft performance for the whole flight envelope. The effect of the flap on the trimming and handling of a full helicopter is also investigated. Fluid and structure dynamics were coupled in all cases, and the rotor was trimmed at different thrust coefficients. The Gurney proved to be efficient at medium to high advance ratios, where the power requirements of the rotor were decreased by up to 3.3%. However, the 1/rev actuation of the flap might be an issue for the trimming and handling of the helicopter. The current study builds on the idea that any active mechanism operating on a rotor could alter the dynamics and the handling of the helicopter. A closed loop actuation of the Gurney flap was put forward based on a pressure divergence criterion, and it led to further enhancement of the aerodynamic performance. Next, a generic light utility helicopter was built using 2D aerodynamics of the main aerofoil section of the W3 Sokol blade along with a robust controller, and the response of the rotorcraft to control inputs was tested. This analysis proved that the 1/Rev actuation of the Gurney did not alter the handling qualities of the helicopter, and as a result, it can be implemented as a flow control mechanism for aerodynamic enhancement and retreating blade stall alleviation.

Keywords

Aircraft designfuture technologiesaerodynamics aircraft design performance
Type
Research Article
Information
The Aeronautical Journal , Volume 120 , Issue 1230 , August 2016 , pp. 1230 - 1261
Copyright
Copyright © Royal Aeronautical Society 2016 

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References

REFERENCES

1. Wang, J.J., Li, Y.C. and Choi, K.S. Gurney flap - Lift enhancement, mechanisms and applications, Progress in Aerospace Sciences, 2008, 44, pp 22–47.Google Scholar
2. Liebeck, R.H. Design of subsonic airfoils for high lift, J. Aircraft, September 1978, 15, (9), pp 547–561.CrossRefGoogle Scholar
3. Jeffrey, D. and Zghang, X. Aerodynamics of Gurney flaps on a single-element high-lift wing, Journal of Aircraft, 2000, 37, (2), pp 295–301.Google Scholar
4. Troolin, D.R., Longmire, E.K. and Lai, W.T. Time resolved PIV analysis of flow over a NACA 0015 airfoil with Gurney flap, Experiments in Fluids, 2006, 41, pp 241–254.Google Scholar
5. Lee, T. and Su, Y.Y. Lift enhancement and flow structure of airfoil with joint trailing-edge flap and Gurney flap, Experiments in Fluids, 2011, 50, pp 1671–1684.Google Scholar
6. Tang, D. and Dowell, E.H. Aerodynamic loading for an airfoil with an oscillating Gurney flap, J. Aircraft, 2007, 44, (4), pp 1245–1257.Google Scholar
7. Chow, R. and Van Dam, C.P. Unsteady computational investigations of deploying load control microtabs, J. Aircraft, September–October 2006, 43, (5), pp 1458–1469.Google Scholar
8. Baker, J.P., Standish, K.J. and Van Dam, C.P. Two-dimensional wind tunnel and computational investigation of a microtab modified airfoil, J. Aircraft, 2007, 44, (2), pp 563–572.Google Scholar
9. Kinzel, M.P., Maughmer, M.D. and Duque, E.P.N. Numerical investigation on the aerodynamics of oscillating airfoils with deployable Gurney flaps, AIAA J., 2010, 48, (7), pp 1457–1469.CrossRefGoogle Scholar
10. Gai, S.L. and Palfrey, R. Influence of trailing-edge flow control on airfoil performance, J. Aircraft, 2003, 40, (2), pp 332–337.CrossRefGoogle Scholar
11. Yeo, H. Assessment of active controls for rotor performance enhancement, J. American Helicopter Society, 2008, 53, (2), pp 152–163.Google Scholar
12. Jeffrey, D., Zhang, X. and Hurst, D.W. Aerodynamics of Gurney flaps on a single-element high-lift wing, J. Aircraft, 2000, 37, (2), pp 295–301.Google Scholar
13. Maughmer, M.D. and Bramesfeld, G. Experimental investigation of Gurney flaps, J. Aircraft, 2008, 45, (6), pp 2062–2067.CrossRefGoogle Scholar
14. Min, B., Sankar, L.N., Rajmohan, N. and Prasad, J.V.R. Computational investigation of Gurney flap effects on rotors in forward flight, J. Aircraft, 2009, 46, (6), pp 1957–1964.Google Scholar
15. Padthe, A.K., Liu, L. and Friedmann, P.P. “Numerical evaluation of microflaps for on blade control of noise and vibration,” Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 2011, Denver, Colorado, US.Google Scholar
16. Bae, E.S. and Gandhi, F. Upstream active Gurney flap for rotorcraft vibration reduction, AHS International, vol. 2, 2012, Ft. Worth, Texas, US, pp 1354–1362.Google Scholar
17. Milgram, J., Chopra, I. and Straub, F. Rotors with trailing edge flaps: Analysis and comparison with experimental data, J. American Helicopter Society, 1998, 43, (4), pp 319–332.CrossRefGoogle Scholar
18. Viswamurthy, S.R. and Ganguli, R. An optimization approach to vibration reduction in helicopter rotors with multiple active trailing edge flaps, Aerospace Science and Technology, 2004, 8, (3), pp 185–194.Google Scholar
19. Yeo, H. Assessment of active controls for rotor performance enhancement, AHS International, vol. 2, 2006, Phoenix, Arizona, US, pp 935–953.Google Scholar
20. Cheng, R.P. and Celi, R. Optimum two-per-revolution inputs for improved rotor performance, J. Aircraft, 2005, 42, (6), pp 1409–1417.CrossRefGoogle Scholar
21. Gagliardi, A. and Barakos, G.N. Analysis and design of a flap-equipped low-twist rotor for hover, J. Aircraft, 2009, 46, (1), pp 74–84.CrossRefGoogle Scholar
22. Lorber, P., Hein, B., Wong, J. and Wake, B. Rotor aeromechanics results from the Sikorsky active flap demonstration rotor, AHS International, 2012, 1, pp 553–568.Google Scholar
23. Pastrikakis, V.P., Steijl, R. and Barakos, G.N. Computational aeroelastic analysis of a hovering W3 Sokol blade with Gurney flap, J. Fluids and Structures, 2014, 53, (1763), pp 96–111.Google Scholar
24. Dehaeze, F. and Barakos, G.N. Hovering rotor computations using an aeroelastic blade model, Aeronautical J., 2012, 116, (1180), pp 621–649.CrossRefGoogle Scholar
25. Dehaeze, F. and Barakos, G.N. Mesh deformation method for rotor flows, J. Aircraft, 2012, 49, (1), pp 82–92.Google Scholar
26. Dehaeze, F. and Barakos, G.N. “Aeroelastic CFD computations for rotor flows,” 37th European Rotorcraft Forum, 2011, Vergiate and Gallarate, Italy, pp 143–162.Google Scholar
27. Steijl, R., Barakos, G. and Badcock, K. A framework for CFD analysis of helicopter rotors in hover and forward flight, Int. J. for Numerical Methods in Fluids, 2006, 51, (8), pp 819–847.Google Scholar
28. Steijl, R. and Barakos, G. Sliding mesh algorithm for CFD analysis of helicopter rotor-fuselage aerodynamics, Int. J. for Numerical Methods in Fluids, 2008, 58, pp 527–549.Google Scholar
29. Barakos, G., Steijl, R., Badcock, K. and Brocklehurst, A. “Development of CFD Capability for full helicopter engineering analysis,” 31st European Rotorcraft Forum, 2005, Florence, Italy.Google Scholar
30. Osher, S. and Chakravarthy, S. Upwind schemes and boundary conditions with applications to Euler equations in general geometries, J. Computational Physics, 1983, (50), pp 447–481.Google Scholar
31. Van Albada, G.D., Van Leer, B. and Roberts, W. A comparative study of computational methods in cosmic gas dynamics, Astron. Astrophysics, 1982, 108, p 76.Google Scholar
32. Jameson, A. “Time dependent calculations using multigrid, with applications to unsteady flows past airfoils and wings,” 110th Computational Fluid Dynamics Conference, AIAA-91-1596, 1991, Honolulu, Hawaii, US.Google Scholar
33. Steijl, R. and Barakos, G. A computational study of the advancing side lift phase problem, J. Aircraft, 2008, 45, (1), pp 246–257.Google Scholar
34. Woodgate, M. and Barakos, G.N. “Rotor computations with active Gurney flaps,” 38th European Rotorcraft Forum, 2012, Amsterdam, Netherlands, (54).Google Scholar
35. Woodgate, M., Pastrikakis, V. and Barakos, G.N. “Rotor computations with active Gurney flaps,” ERCOFTAC International Symposium “Unsteady Separation in Fluid-Structure Interaction”, 2013, Mykonos, Greece.Google Scholar
36. Yang, Z., Sankar, M., Smith, M. and Bauchau, O. Recent improvements to a hybrid method for rotors in forward flight, J. Aircraft, 2002, 39, (5), pp 804–812.Google Scholar
37. Van der Ven, H. and Boelens, O. “A framework for aeroealistic simulations of trimmed rotor systems in forward flight,” European Rotorcraft Forum, 14-16 September 2004, Marseille, France.Google Scholar
38. Park, Y. and Kwon, O. Simulation of unsteady rotor flow field using unstructured adaptive sliding meshes, J. American Helicopter Society, 2004, 49, (4), pp 391–400.CrossRefGoogle Scholar
39. MSC Software Corporation, “MSC.Nastran 2005 Release Guide,” 2005.Google Scholar
40. Goura, G., Badcock, K., Woodgate, M. and Richards, B. “Implicit method for the time marching analysis of flutter, Aeronautical J., 2001, 105, (1046), pp 199–214.Google Scholar
41. Dubuc, L., Cantariti, F., Woodgate, M., Gribben, B., Badcock, K. and Richards, B. A Grid deformation technique for unsteady flow computations, Int J for Numerical Methods in Fluids, 2000, 32, (3), pp 285–311.Google Scholar
42. Woodgate, M.A. and Barakos, G.N. Implicit computational fluid dynamics methods for fast analysis of rotor flows, AIAA J., 2012, 50, (6), pp 1217–1244.CrossRefGoogle Scholar
43. Garkushenko, V.I., Vinogradov, S.S. and Barakos, G.N. “Robust control synthesis for an unmanned helicopter,” 40th European Rotorcraft Forum, September 2014, Southampton, United Kingdom, (72).Google Scholar
44. Advanced Rotorcraft Technology, “http://www.art.com/,” .Google Scholar
45. Kufeld, R., Balough, D., Cross, J., Studebaker, K., Jennison, C. and Bousman, W. “Flight testing of the UH-60A airloads aircraft,” American Helicopter Society 50th Annual Forum Procceedings, Msy 1994, Washington, D.C., US.Google Scholar
46. Yeo, H., Bousman, W.G. and Johnson, W. Performance analysis of a utility helicopter with standard and advanced rotors, J. American Helicopter Society, 2004, 49, (3), pp 250–270.Google Scholar
47. Baskett, B.J. Aeronautical Design Standard Performance Specification Handling Qualities Requirements for Military Rotorcraft, CAGE Code 18876, 21, DTIC Document, 2000.Google Scholar
48. Garcia, A.J. and Barakos, G. “Hover performance predictions for the S-76 main rotor blade,” AIAA 53th Aerospace Sciences Meeting and Exhibit, 2015, Kissimmee, Florida, US.Google Scholar