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Unsteady aerodynamic model of a cargo container for slung-load simulation

Published online by Cambridge University Press:  03 February 2016

L. S. Cicolani,
J. G. A. da Silva,
E. P. N. Duque and
M. B. Tischler
L. S. Cicolani
Affiliation:
Army/NASA Rotorcraft Division, Ames Research Center, Moffett Field California, USA
J. G. A. da Silva
Affiliation:
Army/NASA Rotorcraft Division, Ames Research Center, Moffett Field California, USA
E. P. N. Duque
Affiliation:
Deptartment of Mechanical Engineering, Northern Arizona University, Flagstaff, Arizona, USA
M. B. Tischler
Affiliation:
Army/NASA Rotorcraft Division, Aeroflightdynamics Directorate, (AMRDEC) US Army Research Development and Engineering Command, Moffett Field, California, USA
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Abstract

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The problem of simulation models capable of predicting the aerodynamic instability of helicopter slung-load cargo containers and bluff bodies is addressed. Instability for these loads is known to depend on unsteady frequency-dependent aerodynamics, but simulation models that include the unsteady aerodynamics do not currently exist. This paper presents a method for generating such models using computational fluid dynamics (CFD) to generate forced-oscillation aerodynamic data and frequency domain system identification techniques to generate a frequency response from the CFD data and to identify a transfer function fit to the frequency response. The method is independent of the responsible flow phenomenon and is expected to apply to bluff-bodies generally. Preliminary results are presented for the case of the 6- by 6- by 8-ft CONEX (container express) cargo container. The present work is based on two-dimensional (2D) aerodynamic data for the CONEX side force and yaw moment generated by a forced oscillation in which frequency is varied smoothly over the range of interest. A first-order rational polynomial transfer function is found adequate to fit the aerodynamics, and this is shown to provide a good match with flight test data for the yawing motion of the CONEX.

Information

Type
Research Article
Information
The Aeronautical Journal , Volume 108 , Issue 1085 , July 2004, pp. 357 - 368
Copyright
Copyright © Royal Aeronautical Society 2004 

References

1. Multiservice helicopter external air transport. I (Basic operations), II (Single point load rigging procedures), III (Dual point load rigging procedures), US Army FM-55-450-3,-4,-5. Feb. 1991.Google Scholar
2. Chan, D., Flower, J. and Simpson, A. Aerodynamically induced motions of bluff bodies suspended beneath helicopters, Final report, Report AD, Department of Aeronautical Engineering, University of Bristol, Bristol, UK October 1975.Google Scholar
3. Simpson, A. and Flower, J. Unsteady aerodynamics of oscillating containers and application to the problem of dynamic stability of helicopter underslung loads, AGARD CP235, November 1978.Google Scholar
4. Watkins, T., Sinacori, J. and Kesler, D. Stabilisation of externally slung helicopter loads, US Army Air Mobility Research and Development Laboratory TR-74-42, Aug. 1974.Google Scholar
5. Sampath, P. Dynamics of a Helicopter-Slung Load System. Ph.D. thesis. Department of Aerospace Engineering, U Maryland, College Park, Md, January 1980.Google Scholar
6. Ronen, T. Dynamics of a Helicopter With a Sling Load. PhD. thesis, Stanford University, Stanford, California, August 1985. Also Ronen, T., Bryson, A. and Hindson, W. Dynamics of a helicopter with a sling load, AIAA 86-2288, August 1986.Google Scholar
7. Cicolani, L.S., Mccoy, A.H., Sahai, R., Tyson, P., Tischler, M.B., Ronen, A. and Tucker, G. Flight test identification and simulation of a UH-60A helicopter and slung load, J American Helicopter Society, 2001, 46, pp 140–160.Google Scholar
8. Ronen, A., Cecutta, S. and Yaffe, R. Wind tunnel tests of cube and CONEX models, Report TAE-844, Faculty of Aerospace Engineering, Technion Institute of Technology, Haifa, Israel, November 1999.Google Scholar
9. Tyson, P., Cicolani, L.S., Tischler, M.B., Rosen, A., Levine, D. and Dearing, M. Simulation prediction and flight validation of UH-60A Black Hawk slung load characteristics, 55th AHS Forum Proceedings, May 1999.Google Scholar
10. Buning, P.G., Chiu, I.T., Obayashi, S., Rizk, Y.M. and Steger, J.L. Numerical simulation of the integrated space shuttle vehicle in ascent, AIAA 88-4359, Augugt 1988.Google Scholar
11. Palmer, J., Buning, P.G., Yanowitz, H. and Venkatapathy, E. Three-dimensional computational analysis of complex launch vehicle configurations, J Spacecraft and Rockets, 1996, 33 pp 49–53.Google Scholar
12. Meakin, R. Moving grid overset grid methods for complete aircraft tiltrotor simulations, AIAA 93-3350, July 1993.Google Scholar
13. Ahmad, J. and Duque, E.P.N. Helicopter rotor blade computation in unsteady flows using moving overset grids, J Aircr, 1996, 33, pp 54–60.Google Scholar
14. Chan, W.M. The OVERGRID interface for computational simulations on OVERSET grids, AIAA 2002-3188, June 2002.Google Scholar
15. Thomas, T.G. and Williams, J.J.R. Large eddy simulation of vortex shedding from a cubic obstacle, J Aerospace Engineering, 1999, 12, pp 113–120.Google Scholar
16. Methodology – STAR-CD Version 3.15, Computational Dynamics Limited, 2001. www.adapco.com.Google Scholar
17. Duque, E.P.N., Gordon, R., Berry, M.D., Cicolani, L.S. and Rosen, A. Reynolds-averaged Navier-Stokes simulations of helicopter slung loads. Proceedings, AHS 4th Decennial Specialist’s Conference on Aeromechanics. January 2004.Google Scholar
18. Cicolani, L.S., Da Silva, J.G.A., Duque, E.P.N. and Tischler, M.B. Unsteady aerodynamic model of a cargo container for slung load simulation: Preliminary aerodynamic data and model identification, NASA TM-2004-212817, May 2004.Google Scholar
19. Okajima, A. Strouhal numbers of rectangular cylinders, J Fluid Mech, 1982, 123, pp 379–398.Google Scholar
20. Northern Arizona University, Department of Mechanical Engineering, Flagstaff Arizona, (accessed April 2004). URL http://www.cet.nau.edu/~end2/Research/Rotorcraft/cube/mou_spr03/static_pressure_x.mpg www.cet.nau.edu/~end2/Research/Rotorcraft/cube/mou_spr03/static_pressure_z.mpg www.cet.nau.edu/~end2/Research/Rotorcraft/cube/mou_spr03/motion-pressure_x.mpg www.cet.nau.edu/~end2/Research/Rotorcraft/cube/mou_spr03/motion_ pressure_z.mpg Google Scholar
21. Tischler, M.B. and Cauffman, M.G. Frequency-response method for rotorcraft system identification: Flight applications to BO-105 coupled rotor/fuselage dynamics, J of the American Helicopter Society, 1992, 37, pp 3–17.Google Scholar
22. Tischler, M.B. and Cauffman, M.G. Comprehensive identification from frequency responses: An interactive facility for system identification and verification, NASA Conference Publication 10149, Moffett Field, California, September 1994.Google Scholar
23. ERCOFTAC Test Case LES2: Flow past a long square cylinder. U. of Surrey, Guildford, UK February 1998. URL http://vortex.mech.surrey.ac.uk/LESig/les2/ (accessed April 2004).Google Scholar
24. Pulliam, T.H. and Steger, J.L. Implicit finite-difference simulations of three dimensional compressible flow, AIAA J., 1980, 18, pp 159–167.Google Scholar
25. Baldwin, B.S. and Barth, T.J. A One-equation turbulence transport model for high Reynolds number wall-bounded flows, NASA TM-102847, August 1990.Google Scholar