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Consideration of structural constraints in passive rotor blade design for improved performance

Published online by Cambridge University Press:  27 January 2016

J. W. Lim*
Affiliation:
US Army Aviation Development Directorate – AFDD, Aviation & Missile Research, Development & Engineering Center, Research, Development and Engineering Command (RDECOM), Ames Research Center, California, USA

Abstract

This design study applied parameterisation to rotor blade for improved performance. In the design, parametric equations were used to represent blade planform changes over the existing rotor blade model. Design variables included blade twist, sweep, dihedral, and radial control point. Updates to the blade structural properties with changes in the design variables allowed accurate evaluation of performance objectives and realistic structural constraints – blade stability, steady moments (flap bending, chord bending, and torsion), and the high g manoeuvring pitch link loads. Performance improvement was demonstrated with multiple parametric designs. Using a parametric design with advanced aerofoils, the predicted power reduction was 1·0% in hover, 10·0% at μ = 0·30, and 17·0% at μ = 0·40 relative to the baseline UH-60A rotor, but these were obtained with a 35% increase in the steady chord bending moment at μ = 0·30 and a 20% increase in the half peak-to-peak pitch link load during the UH-60A UTTAS manoeuvre Low vibration was maintained for this design. More rigorous design efforts, such as chord tapering and/or structural redesign of the blade cross section, would enlarge the feasible design space and likely provide significant performance improvement.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2015

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References

1Lim, J.W. and Chopra, I.Aeroelastic optimization of a helicopter rotor using an efficient sensitivity analysis, J Aircraft, January 1991, 28, (1), pp 2937.Google Scholar
2Celi, R. and Friedmann, P.P.Structural optimization with aeroelastic constraints of rotor blades with straight and swept tips, 1990, AIAA J, 28, (5), pp 928936.Google Scholar
3Friedmann, P.P.Helicopter vibration reduction using structural optimization with aeroelastic/multidisciplinary constraints – a survey, J Aircraft, January 1991, 28, (1), pp 821.Google Scholar
4Celi, R.Recent applications of design optimization to rotorcraft – A survey, J Aircraft, 36, (1), January-February 1999, pp176189.Google Scholar
5Ganguli, R.Survey of recent developments in rotorcraft design optimization, J Aircraft, May-June 2004, 41, (3), pp 493510.Google Scholar
6Imiela, M. and Wilke, G.Passive Blade Optimization and Evaluation in Off-Design Conditions, 39th European Rotorcraft Forum Proceedings, Moscow, Russia, 3-5 September, 2013.Google Scholar
7Johnson, C.S. and Barakos, G.N.Optimising Aspects of Rotor Blades in Forward Flight, Proceedings of the 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 4-7 January 2011, Orlando, Florida, US.Google Scholar
8Min, B.Y., Sankar, L.N., Collins, K. and Brentner, K.S.CFD-CSD Coupled Study in the BVI Characteristics of a Saw-Tooth Blade Planform, American Helicopter Society 67th Annual Forum Proceedings, Virginia Beach, Virginia, US, 3-5 May 2011.Google Scholar
9Leon, E.R., Le Pape, A., Desideri, J., Alfano, D. and Costes, M.Concurrent Aerodynamic Optimization of Rotor Blades Using a Nash Game Method, American Helicopter Society 69th Annual Forum Proceedings, Phoenix, Arizona, US, 21-23 May, 2013.Google Scholar
10Mishra, A., Mani, , Karthik, , Mavriplis, D. and Sitaraman, J.Time-dependent Adjoint-based Aerodynamic Shape Optimization Appied to Helicopter Rotors, American Helicopter Society 70th Annual Forum Proceedings, Montreal, Canada, 20-22 May 2014.Google Scholar
11Naik, K.R., Economon, T.D., Colonno, M.R., Palacios, F. and Alonso, J.J.A Time-Spectral Adjoint Formulation for Shape Optimization of Helicopters in Forward Flight, American Helicopter Society 69th Annual Forum Proceedings, Phoenix, Arizona, US, 21-23 May, 2013.Google Scholar
12Ortun, B., Bailly, J., des Rochettes, H.M. and Delrieux, Y.Recent Advances in Rotor Aerodynamic Optimization, Including Structural Data Update, 5th Decennial American Helicopter Society Specialists’ Conference Proceedings, San Francisco, California, US, 22-24 January 2014.Google Scholar
13Potsdam, M., Yeo, H. and Johnson, W.Rotor airloads prediction using loose aerodynamic/structural coupling, J Aircraft, May-June 2006, 43, (3), pp 732742.Google Scholar
14Adams, B.The dakota toolkit for parallel optimization and uncertainty analysis, SIAM Conference on Optimization Proceedings, Boston, Massachusetts, US, May 2008.Google Scholar
15Johnson, W.Rotorcraft Aerodynamic Models for a Comprehensive Analysis, Proceedings of the 54th Anual Forum of the American Helicopter Society, Washington, DC, US, 20-22 May 1998.Google Scholar
16Brocklehurst, A. and Barakos, G.N.A review of helicopter rotor blade tip shapes, Progress in Aerospace Sciences, Elsevier Company, 2013, 56, pp 3574.Google Scholar
17Rauch, P., Gervais, M., Cranga, P., Baud, A., Hirsch, J-F, Walter, A. and Beaumier, P.Blue EdgeTM: The Design, Developmen. and Testing of a New Blade Concept, American Helicopter Society 67th Annual Forum Proceedings, Virginia Beach, Virginia, US, 3-5 May 2011.Google Scholar
18Shinoda, P. M., Norman, T. R., Jacklin, S. A., Yeo, H., Bernhard, A. P. F. and Haber, A.Investigation of a Full-Scale Wide Chord Blade Rotor System in the NASA Ames 40- by 80-Foot Wind Tunnel, American Helicopter Society 4th Decennial Specialist’s Conference on Aeromechanics Proceedings, San Francisco, California, US. 21-23 January, 2004.Google Scholar
19Hodges, D.H. and Dowell, E.H. Nonlinear Equations of Motion for the Elastic Bending and Torsion of Twisted Nonuniform Rotor Blades, NASA TN D-7818, December 1974.Google Scholar
20Crews, S.T. and Hamilton, B.W.Army Helicopter Crew Seat Vibration – Past Performance, Future Requirements, Proceedings of the American Helicopter Society North East Region National Specialists’ Meeting on Helicopter Vibration, Hartford, Connecticut, US. November 1981.Google Scholar
21 Anonymous, Requirements for Rotorcraft Vibration, Specifcations, Modeling and Testing, Aeronautical Design Standard ADS-27A-SP, US Army Aviation Systems Command, Redstone Arsenal, Alabama, US, May 2006.Google Scholar
22Norman, T.R., Shinoda, P., Peterson, R.L. and Datta, A.Full-Scale Wind Tunnel Test of the UH-60A Airloads Rotor, American Helicopter Society 67th Annual Forum Proceedings, Virginia Beach, Virginia, US, 3-5 May 2011.Google Scholar
23Romander, E., Norman, T.R. and Chang, I-C.Correlating CFD Simulation with Wind Tunnel Test for the Full-Scale UH-60A Airloads Rotor, American Helicopter Society 67Th Annual Forum, Virginia Beach, Virginia, 3-5 May 2011.Google Scholar
24Yeo, H. and Romander, E.A.Loads Correlation of a Full-Scale UH-60A Airloads Rotor in a Wind Tunnel, American Helicopter Society 68th Annual Forum Proceedings, Fort Worth, Texas, US, 1-3 May 2012.Google Scholar
25Bousman, W. G. and Kufeld, R.M. UH-60A Airloads Catalog, NASA TM-2005-212827, August 2005.Google Scholar
26Bhagwat, M.J. and Ormiston, R.A.Examination of Rotor Aerodynamics in Steady and Manoeuvreing Flight Using CFD and Conventional Methods, American Helicopter Society Specialist’s Conference on Aeromechanics Proceedings, San Francisco, California, US, January 2008.Google Scholar
27Yeo, H., Bousman, W.G. and Johnson, W.Performance Analysis of a Utility Helicopter with Standard and Advanced Rotors, American Helicopter Society Aerodynamics, Acoustic. and Test an Evaluation Technical Specialists Meeting Proceedings, San Francisco, California, US, January 2002Google Scholar