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CFD analysis of hover performance of rotors at full- and model-scale conditions

Published online by Cambridge University Press:  13 June 2016

G.N. Barakos*
Affiliation:
CFD Laboratory, School of Engineering, James Watt South Building, University of Glasgow, Glasgow, United Kingdom
A. Jimenez Garcia
Affiliation:
CFD Laboratory, School of Engineering, James Watt South Building, University of Glasgow, Glasgow, United Kingdom

Abstract

Analysis of the performance of a 1/4.71 model-scale and full-scale Sikorsky S-76 main rotor in hover is presented using the multi-block computational fluid dynamics (CFD) solver of Glasgow University. For the model-scale blade, three different tip shapes were compared for a range of collective pitch and tip Mach numbers. It was found that the anhedral tip provided the highest Figure of Merit. Rigid and elastic full-scale S-76 rotor blades were investigated using a loosely coupled CFD/Computational Structural Dynamics (CSD) method. Results showed that aeroelastic effects were more significant for high thrust cases. Finally, an acoustic study was performed in the tip-path-plane of both rotors, showing good agreement in the thickness and loading noise with the theory. For the anhedral tip of the model-scale blade, a reduction of 5% of the noise level was predicted. The overall good agreement with the theory and experimental data demonstrated the capability of the present CFD method to predict rotor flows accurately.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2016 

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References

REFERENCES

1. Brocklehurst, A. and Barakos, G.N. A review of helicopter rotor blade tip shapes, Progress in Aerospace Sciences, 2013, 56, (1), pp 3574, DOI: 10.1016/j.paerosci.2012.06.003.CrossRefGoogle Scholar
2. Johnson, W. Helicopter Theory, 1980, Princeton University Press, Princeton, New Jersey, US.Google Scholar
3. Balch, D.T., Saccullo, A. and Sheehy, T.W. Experimental study of main rotor/tail rotor/airframe interactions in hover - Volume I, NASA CR–166485, June 1983.Google Scholar
4. Balch, D.T. Experimental study of main rotor/tail rotor/airframe interactions in hover, J. American Helicopter Society, 1985, 30, (2), pp 4956, DOI:http://dx.doi.org/10.4050/JAHS.30.49.Google Scholar
5. Balch, D.T. and Lombardi, J. Experimental study of main rotor tip geometry and tail rotor interactions in hover. Vol I - text and figures, NASA CR–177336, February 1985.Google Scholar
6. Balch, D.T. and Lombardi, J. Experimental study of main rotor tip geometry and tail rotor interactions in hover. Vol II - run log and tabulated data progress report, NASA CR–177336, February 1985.Google Scholar
7. Johnson, W. Performance and loads data from a wind tunnel test of a full-scale rotor with four blade tip planforms, NASA TM–81229, September 1980.Google Scholar
8. Jepson, D., Moffitt, R., Hilzinger, K. and Bissell, J. Analysis and correlation of test data from and advanced technology rotor system, NASA CR–3714, August 1983.Google Scholar
9. Shinoda, P.M. Performance results from a test of an S-76 rotor in the NASA Ames 80- by 120- foot wind tunnel, Proceedings of the 11th Applied Aerodynamics Conference, 1993, AIAA, Monterey, California, US, pp 126-144.Google Scholar
10. Shinoda, P.M. Full-scale S-76 rotor performance and loads at low speeds in the NASA Ames 80-by 120-foot wind tunnel, NASA TM–110379, April 1996.Google Scholar
11. Swanson, A.A. Application of the shadowgraph flow visualisation technique to a full-scale helicopter rotor in hover and forward flight, Proceedings of the 11th Applied Aerodynamics Conference, 1993, AIAA, Monterey, California, US, pp 1-15.Google Scholar
12. Hariharan, N., Egolf, A. and Sankar, L. Simulation of rotor in hover: current state and challenges, Proceedings of the 52nd Aerospace Sciences Meeting, 2014, AIAA, National Harbor, Maryland, US, pp 1-28.Google Scholar
13. Hariharan, N., Egolf, A. and Sankar, R. N.L. Helicopter rotor aerodynamic modeling in hover: AIAA standardized hover evaluations, Proceedings of the 53rd Aerospace Sciences Meeting, 2015, AIAA, Kissimmee, Florida, US, pp 1-34.Google Scholar
14. Baeder, J.D., Medida, S. and Kalra, T.S. OVERTURNS simulations of S-76 rotor in hover, Proceedings of the 52nd Aerospace Sciences Meeting, 2014, AIAA, National Harbor, Maryland, US, pp 1-11.Google Scholar
15. Sheng, C., Zhao, Q. and Wang, J. S-76 rotor hover prediction using U2NCLE solver, Proceedings of the 52nd Aerospace Sciences Meeting, 2014, AIAA, National Harbor, Maryland, US, pp 1-19.Google Scholar
16. Langtry, R.B. A Correlation-Based Transition Model using Local Variables for Unstructured Parallelized CFD codes, PhD Thesis, May 2006, University of Stuttgart, Germany.Google Scholar
17. Langtry, R.B. and Menter, F.R. Correlation-based transition modeling for unstructured parallelized computational fluid dynamics codes, AIAA J., 2010, 47, (12), pp 28952906, DOI: 10.2514/1.42362.Google Scholar
18. Jain, R.K. and Potsdam, M.A. Hover predictions on the Sikorsky S-76 rotor using Helios, Proceedings of the 52nd Aerospace Sciences Meeting, 2014, AIAA, National Harbor, Maryland, US, pp 1-21.Google Scholar
19. Jain, R. Hover predictions for the S-76 rotor with tip shape variation using CREATE-AV Helios, Proceedings of the 53rd Aerospace Sciences Meeting, 2015, AIAA, Kissimmee, Florida, US, pp 1-29.Google Scholar
20. Liu, Z., Kim, J., Sankar, L., Hariharan, N. and Egolf, T.A. High order evaluation of S-76 in hover, Proceedings of the 53rd Aerospace Sciences Meeting, 2015, AIAA, Kissimmee, Florida, US, pp 1-9.Google Scholar
21. Marpu, R.P., Sankar, L.N., Egolf, T.A. and Hariharan, N. Analysis of rotor in hover using hybrid methodology, Proceedings of the 52nd Aerospace Sciences Meeting, 2014, AIAA, National Harbor, Maryland, US, pp 1-11.Google Scholar
22. Kim, J.W., Sankar, L.N., Marpu, R., Egolf, T.A. and Hariharan, N. Assessment of planform effects on rotor hover performance, Proceedings of the 53rd Aerospace Sciences Meeting, 2015, AIAA, Kissimmee, Florida, US, pp 1-12.Google Scholar
23. Tadghighi, H. Helios simulation of rotors in hover: The Boeing company, Proceedings of the 52nd Aerospace Sciences Meeting, 2014, AIAA, National Harbor, Maryland, US, pp 1-9.Google Scholar
24. Narducci, R. OVERFLOW simulation of rotors in hover: The Boeing company, Proceedings of the 52nd Aerospace Sciences Meeting, 2014, AIAA, National Harbor, Maryland, US, pp 1-9.CrossRefGoogle Scholar
25. Narducci, R. Hover performance assessment of several tip shapes using OVERFLOW, Proceedings of the 53rd Aerospace Sciences Meeting, 2015, AIAA, Kissimmee, Florida, US, 2015, pp 1-19.Google Scholar
26. Inthra, P.A. The effects of turbulence modelings on CFD simulations of S76 hovering rotor, Proceedings of the 53rd Aerospace Sciences Meeting, 2015, AIAA, Kissimmee, Florida, US, pp 1-14.Google Scholar
27. Abras, J.N. and Hariharan, N. Comparison of CFD hover predictions on the S-76 rotor, Proceedings of the 53rd Aerospace Sciences Meeting, 2015, AIAA, Kissimmee, Florida, US, pp 1-11.Google Scholar
28. Wachspress, D.A., Quackenbush, T.R. and Boschitsch, A.H. First-principles free-vortex wake analysis for helicopters and tiltrotors, Proceedings of the 59th Annual Forum, 2003, AHS, Phoenix, AZ, pp 1-24.Google Scholar
29. Jimenez, A. and Barakos, G.N. Hover predictions on the S-76 rotor using HMB2, Proceedings of the 53rd Aerospace Sciences Meeting, 2015, AIAA, Kissimmee, Florida, US, pp 1-34.Google Scholar
30. Bousman, W.G. Aerodynamic characteristics of SC1095 and SC1094R8 airfoils, NASA TP–2003-212265, December 2003.Google Scholar
31. Lawson, S.J., Steijl, R., Woodgate, M. and Barakos, G.N. High performance computing for challenging problems in computational fluid dynamics, Progress in Aerospace Sciences 2012, 2012, 52, (1), pp 1929, DOI: 10.1016/j.paerosci.2012.03.004.Google Scholar
32. Steijl, R. and Barakos, G.N. Sliding mesh algorithm for CFD analysis of helicopter rotor-fuselage aerodynamics, Int. J. for Numerical Methods in Fluids, 2008, 58, (5), pp 527549, DOI: 10.1002/d.1757.Google Scholar
33. Barakos, G., Steijl, R., Badcock, K. and Brocklehurst, A. Development of CFD capability for full helicopter engineering analysis, Proceedings of the 31st European Rotorcraft Forum, 2005, ERF, Florence, Italy, pp 1-15.Google Scholar
34. Steijl, R., Barakos, G.N. and Badcock, K. A framework for CFD analysis of helicopter rotors in hover and forward flight, Int. J. Numerical Methods in Fluids, 2006, 51, (8), pp 819847, DOI: 10.1002/d.1086.Google Scholar
35. Hirt, C.W., Amsten, A.A. and Cook, J.L. An arbitrary Lagrangian-Eulerian computing method for all flow speeds, J. Computational Physics, 1974, 14, (3), pp 227253, DOI: 10.1016/0021-9991(74)90051-5.Google Scholar
36. Osher, S. and Chakravarthy, S. Upwind schemes and boundary conditions with applications to euler equations in general geometries, J. Computational Physics, 1983, 50, (3), pp 447481, DOI: 10.1016/0021-9991(83)90106-7.Google Scholar
37. van Leer, B. Towards the ultimate conservative difference scheme. V. A second-order sequel to Godunov’s method, J. Computational Physics, 1979, 32, (1), pp 101136, DOI: 10.1016/0021-9991(79)90145-1.Google Scholar
38. van Albada, G.D., van Leer, B. and Roberts, W.W. A comparative study of computational methods in cosmic gas dynamics, Astronomy and Astrophysics, 1982, 108, (1), pp 7684.Google Scholar
39. Axelsson, O. Iterative Solution Methods, 1994, Cambridge University Press.Google Scholar
40. Jameson, A., Schmidt, W. and Turkel, E. Numerical solutions of euler equations by finite volume methods using Runge-Kutta time-stepping schemes, Proceedings of the 14th Fluid and Plasma Dynamic Conference, 1981, AIAA, Palo Alto, California, US, pp 1-19.Google Scholar
41. Menter, F.R. Two-equation Eddy-Viscosity turbulence models for engineering applications, AIAA J., 1994, 32, (8), pp 15981605, DOI: 10.2514/3.12149.CrossRefGoogle Scholar
42. Brocklehurst, A. High Resolution Method for the Aerodynamic Design of Helicopter Rotors, PhD Thesis, June 2013, University of Liverpool, UK.Google Scholar
43. Kocurek, J.D. and Tangler, J.L. A prescribed wake lifting surface hover performance analysis, J. the American Helicopter Society, 1977, 22, (1), pp 2435, DOI: 10.4050/JAHS.22.24.Google Scholar
44. Landgrebe, A.J. The wake geometry of a hovering rotor and its influence on rotor performance, J. the American Helicopter Society, 1972, 17, (4), pp 315, DOI: 10.4050/JAHS.17.3.Google Scholar
45. Jeong, J. and Hussain, F. On the identification of a vortex, J. Fluid Mechanics, 1995, 285, (1), pp 6994, DOI: 10.1017/S0022112095000462.Google Scholar
46. Makofski, R.A. Charts for estimating the hovering endurance of a helicopter, NACA TN 3810, Langley Aeronautical Laboratory, October 1956.Google Scholar
47. Ffowcs-Williams, J.E. and Hawkings, D.L. Sound generation by turbulence and surfaces in arbitrary motion, J. Computational Physics, 1969, 264, (1), pp 321342, DOI: 10.1098/rsta.1969.0031.Google Scholar
48. Lighthill, M.J. On sound generated aerodynamically. I. General theory, Proceedings of the Royal Society 221A, 1952.Google Scholar
49. Brentner, K.S. and Farassat, F. Modeling aerodynamically generated sound of helicopter rotors, Progress in Aerospace Sciences, 2003, 39, (2), pp 83120, DOI: 10.1016/S0376-0421(02)00068-4.Google Scholar
50. Gopalan, G. and Shmitz, F. Understanding far field near-in-plane high speed harmonic helicopter rotor noise in hover: Governing parameters and active acoustic control possibilities, Proceedings of Specialist’s Conference on Aeromechanics, AHS, San Francisco, CA, 64, pp 1-23.Google Scholar
51. Gopalan, G. and Shmitz, F.H. Far-field near-in plane harmonic main rotor helicopter impulsive noise reduction possibilities, Proceedings of the 64th Annual Forum, 2008, AHS, Montréal, Canada, 64, pp 1-22.Google Scholar
52. Kusyumov, A.N., Mikhailov, S.A., Garipova, L.I., Batrakov, A.S. and Barakos, G. Prediction of helicopter rotor noise in hover, EPJ Web of Conferences, 2015, 92, (02042), pp 1-5, DOI: 10.1051/epjconf/20159202042.Google Scholar
53. Stroub, R.H., Rabbott, J.P. and Niebanck, C.F. Rotor blade tip shape effects on performance and control loads from full-scale wind tunnel testing, J. American Helicopter Society, 1979, 24, (5), pp 2835, DOI: http://dx.doi.org/10.4050/JAHS.24.28.Google Scholar
54. Balch, D.T. Correlation of full scale wind tunnel test data with model rotor test data and theory for a modern helicopter main rotor, J. American Helicopter Society, 1979, 24, (4), pp 4550, DOI: http://dx.doi.org/10.4050/JAHS.24.45.Google Scholar
55. Hamade, K.S. and Kufeld, R.M. Modal analysis of UH-60A instrumented rotor blades, NASA TR–4239, August 1990.Google Scholar
56. Monico, M.R. Reduced Weight Rotor Blades as a Result of Flap-Bending Torsion Coupling, August 2013, Rensselaer Polytechnic Institute, Hartford, Connecticut, US.Google Scholar
57. Singleton, J.D. and Yeager, W.T. Important scaling parameters for testing model-scale helicopter rotors, Proceedings of the 20th Advanced Measurement and Ground Testing Technology Conference, 1998, AIAA, Albuquerque, New Mexico, US, pp 1-11.Google Scholar
58. Yamauchi, G.K. and Johnson, W. Trends of Reynolds number effects on two-dimensional airfoil characteristics for helicopter rotor analyses, NASA TM–84363, April 1983.Google Scholar