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Evaluating ship superstructure aerodynamics for maritime helicopter operations through CFD and flight simulation

Published online by Cambridge University Press:  04 July 2016

J.S. Forrest*
Affiliation:
Senior Fluids Engineer, Prism Defence Ltd, North Adelaide, South Australia, Australia
C.H. Kaaria
Affiliation:
Jaguar Land Rover, Gaydon, United Kingdom
I. Owen
Affiliation:
School of Engineering, University of Liverpool, Liverpool, United Kingdom

Abstract

The unsteady air flow over and around the helicopter landing deck of a naval vessel is known to cause high pilot workload and to limit the helicopter's operational envelope for launch and recovery. Previous research has suggested that modifications to the ship's hangar edges can beneficially modify the flow over the deck. This paper examines the effectiveness of five hangar-edge modifications using computational fluid dynamics–generated airwakes and flight mechanics modelling, as well as piloted flight trials in a motion-base simulator. Results are presented, in terms of unsteady helicopter loads and pilot workload ratings, for modifications to the windward vertical rear edge of the hangar and with an oblique wind. The results demonstrate that while the airwake can be altered by superstructure modifications, the integrated effect of the altered airwake on the entire helicopter does not necessarily give the desired result; indeed of the five modifications tested, two were seen to be beneficial while three caused an increase in pilot workload compared with the unmodified hangar. Overall, the paper shows that the airwake can be modified by superstructure design changes, and that the effect on the helicopter can be measured through modelling and simulation. It is also demonstrated that making judgements on the severity of the airwake based on the aerodynamic flow field alone can be misleading. The benefit of these simulation tools is that they can be used during the ship design process to evaluate the effect of the superstructure aerodynamics, rather than wait until after the ship is built.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2016 

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References

REFERENCES

1. Lumsden, B. and Padfield, G.D. Challenges at the helicopter-ship dynamic interface, Military Aerospace Technologies - Fitec ’98, IMechE Conference Transactions, Institution of Mechanical Engineers, London, UK, 1998, pp 89122.Google Scholar
2. Newman, S. The safety of shipborne helicopter operation, Aircraft Engineering and Aerospace Technology, 2004, 76, (5), pp 487501.Google Scholar
3. Johns, LCdr. M.K. and Van Healey, J. The airwake of a DD-963 class destroyer, Naval Engineers J., May 1989, 101, (3), pp 3642.Google Scholar
4. Val Healey, J. The aerodynamics of ship superstructures, Proceedings of the AGARD Flight Mechanics Panel Symposium on Aircraft/Ship Operations, 20-23 May 1991, Seville, Spain.Google Scholar
5. Zan, S.J. Surface flow topology for a simple frigate shape, Canadian Aeronautics and Space J., 2001, 47, (1), pp 3343.Google Scholar
6. Polsky, S.A. A computational study of unsteady ship airwake, 40th AIAA Aerospace Sciences Meeting and Exhibit, 14-17 January 2002, Reno, Nevada, US.Google Scholar
7. Crow, A., Osborne, N. and McCrimmon, A. Flight deck and aviation facility designs for future frigates and destroyers, RINA Warship 2009, 17-18 June 2009, London, UK.Google Scholar
8. Czerwiec, R.M. and Polsky, S.A. LHA airwake wind tunnel and CFD comparison with and without bow flap, 22nd AIAA Applied Aerodynamics Conference and Exhibit, vol. 1, 16-19 August 2004, Providence, Rhode Island, US, pp 207–214.Google Scholar
9. Findlay, D.B. and Ghee, T. Experimental investigation of ship airwake flow control for a US navy flight II-A class destroyer (DDG), 3rd AIAA Flow Control Conference, vol. 3, 5-8 June 2006, San Francisco, California, US, pp 1303–1313.CrossRefGoogle Scholar
10. Kaaria, C.H., Wang, Y., White, M.D. and Owen, I. An experimental technique for evaluating the aerodynamic impact of ship superstructures on helicopter operations, Ocean Engineering, 2013, 61, pp 97108.Google Scholar
11. Investigation of airwake control for safer shipboard aircraft operations, Technical report, June 2007 RTO-TR-AVT-102, NATO Research and Technology Organisation.Google Scholar
12. Modelling and simulation of the ship environment for safer aircraft launch and recovery, Technical report, February 2012, RTO-TR-AVT-148, NATO Research and Technology Organisation.Google Scholar
13. Forrest, J.S. and Owen, I. An investigation of ship airwakes using detached-eddy simulation, Computers & Fluids, 2010, 39, (4), pp 656673.Google Scholar
14. Cheney, B.T. and Zan, S.J. CFD code validation data and flow topology for the technical co-operation program AER-TP2 simple frigate shape, Technical report, April 1999, LTR-A-035, NRCCNRC.Google Scholar
15. Syms, G.F. Numerical simulation of frigate airwakes, Int. J. Computational Fluid Dynamics, 2004, 18, (2), pp 199207.Google Scholar
16. Roper, D.M., Owen, I. and Padfield, G.D. CFD Investigation of the helicopter-ship dynamic interface, American Helicopter Society 61st Annual Forum, vol. 2, 1–3 June 2005, Grapevine, Texas, US, pp 19852002.Google Scholar
17. Syms, G.F. Simulation of simplified-frigate airwakes using a lattice-Boltzmann method, J. Wind Engineering and Industrial Aerodynamics, 2008, vol. 96, (6–7), pp 11971206.Google Scholar
18. McRuer, D.T. Interdisciplinary interactions and dynamic systems integration, Int. J. Control, 1994, 59, (1), pp 312.Google Scholar
19. Comte, P., Daude, F. and Mary, I. Simulation of the reduction of unsteadiness in a passively controlled transonic cavity flow, J. Fluids and Structures, November 2008, 24 (8), pp 12521261.Google Scholar
20. Hodge, S.J., Forrest, J.S., Padfield, G.D. and Owen, I. Simulating the environment at the helicopter-ship dynamic interface: Research, development and Application, Aeronautical J., 2012, 116, (1185), pp 11551184.Google Scholar
21. Forrest, S.J., Owen, I., Padfield, G.D. and Hodge, S.J. Ship-helicopter operating limits prediction using piloted flight simulation and time-accurate airwakes, J. Aircraft, 2012, 49, (4), pp 10201031.Google Scholar
22. Duval, R.W. A real-time multi-body dynamics architecture for rotorcraft simulation, RAeS Flight Simulation Group Conference on ‘The Challenge in Achieving Realistic Training in Advanced Rotorcraft Simulators’, November 2001, London, UK.Google Scholar
23. Kaaria, C.H., Forrest, J.S. and Owen, I. The virtual AirDyn: A simulation technique for evaluating the aerodynamic impact of ship superstructures on helicopter operations, Aeronautical J., 2013, 117, (1198), pp 12331248.Google Scholar
24. Spalart, P.R., Jou, W.H., Strelets, M. and Allmaras, S.R. Comments on the feasibility of LES for wings, and on a hybrid RANS/LES approach, Advances in DNS/LES, In Proceedings of 1st International Conference on DNS/LES, Ruston, Louisiana, August 4-8, 1997, Greyden Press, pp 137147.Google Scholar
25. Peric, M. Flow simulation using control volumes of arbitrary polyhedral shape, ERCOFTAC Bulletin No. 62, ERCOFTAC, 2004, pp 25–29.Google Scholar
26. Manimala, B.J., Walker, D.J., Padfield, G.D., Voskuijl, M. and Gubbles, A.W. Rotorcraft simulation modelling and validation for control law design, Aeronaut J., February 2007, 116, (1116), pp 7788.Google Scholar
27. Howlett, J.J. UH-60A black hawk engineering simulation program: Volume I – mathematical model, NASA-CR-166309, December 1981.Google Scholar
28. Beck, C.P. and Funk, J.D. Development and validation of a seahawk blade element helicopter model in support of rotorcraft shipboard operations, RAeS Rotorcraft Group Conference on ‘Rotorcraft Simulation’, May 1994, London, UK.Google Scholar
29. Padfield, G.D. Helicopter Flight Dynamics, 2nd ed., Blackwell, Oxford, UK, 2007.Google Scholar
30. Crozon, C., Steijl, R. and Barakos, G. Numerical simulations of helicopter rotors in a ship airwake, J. Aircraft, 2014, 51, (6), pp 18131832.Google Scholar
31. Lee, R.G. and Zan, S.J. Unsteady aerodynamic loading on a helicopter fuselage in a ship airwake, J. American Helicopter Society, April 2004, 47, (2), pp 149159.Google Scholar
32. Lee, R.G. and Zan, S.J. Wind tunnel testing of a helicopter fuselage and rotor in a ship airwake, 29th European Rotorcraft Forum, September 2003, Freidrichstrafen, Germany.Google Scholar
33. White, M.D., Perfect, P., Padfield, G.D., Gubbels, A.W. and Berryman, A.C. Acceptance testing and commissioning of a flight simulator for rotorcraft simulation fidelity research, Proceedings of the Institution of Mechanical Engineers, Part G: J Aerospace Engineering, 2013, 227, (4), pp 663686.CrossRefGoogle Scholar
34. Roscoe, M. F. and Thompson, Capt. J. H. JSHIP's dynamic interface modeling and simulation system: A simulation of the UH-60A helicopter/LHA shipboard environment task, American Helicopter Society 59th Annual Forum, 6-8 May 2003, Phoenix, Arizona, US.Google Scholar
35. Scott, P, White, M.D. and Owen, I. The effect of ship size on airwake aerodynamics and maritime helicopter operations, 41st European Rotorcraft Conference, 1-4 September 2015, Munich, Germany.Google Scholar