59th American Helicopter Society International Annual Forum 2003 Phoenix, Arizona, USA 6 – 8 May 2003 Volume 1 of 3 ISBN: 978-1-61782-934-5 Printed from e-media with permission by: Curran Associates, Inc. 57 Morehouse Lane Red Hook, NY 12571 Some format issues inherent in the e-media version may also appear in this print version. Copyright© (2003) by the American Helicopter Society International All rights reserved. Printed by Curran Associates, Inc. (2011) For permission requests, please contact the American Helicopter Society International at the address below. American Helicopter Society International 217 N. Washington Street Alexandria, VA 22314-2538 Phone (703) 684-6777 Fax: (703) 739-9279 [email protected] Additional copies of this publication are available from: Curran Associates, Inc. 57 Morehouse Lane Red Hook, NY 12571 USA Phone: 845-758-0400 Fax: 845-758-2634 Email: [email protected] Web: www.proceedings.com TABLE OF CONTENTS Volume 1 INTEGRATED MANUFACTURING PROCESS & CONTROL TECHNOLOGY I – COMPOSITES TECHNOLOGY Environmental Noise Modelling for UK Military Helicopter Training Operations.........................................................1 R. Munt, R. Browne, C. Simpson, S. Bradley, Y. Lam, G. Kerry, R. Beaman ACOUSTICS Longitudinal-Plane Simultaneous Non-Interfering Approach Trajectory Design for Noise Minimization ........................................................................................................................................................................ 14 G. Gopalan, M. Xue, E. Atkins, F. Schmitz Design and Analysis of High-Frequency Periodically Layered Isolators with Passive Design Enhancement for Helicopter Gearbox Isolation ............................................................................................................... 32 J. Szefi, E. Smith, G. Lesieutre Transonic Helicopter Noise................................................................................................................................................. 46 A. Morgans, S. Karabasov, A. Dowling, T. Hynes Near Real-Time Simulation of Rotorcraft Acoustics and Flight Dynamics.................................................................... 56 K. Brentner, L. Lopes, H. Chen, J. Horn Helicopter Acoustic Characterization by Simulation: Comparison with Flight Test Results and Predicted Impact of New Design Solutions........................................................................................................................ 71 R. Ponza AERODYNAMICS I – APPLIED AERODYNAMICS Experimental Characterization of the Transition Bubble on a NACA0012 Oscillating Airfoil.................................... 86 E. Berton, C. Maresca, D. Favier Dynamic Stall Measurements and Computations for a VR-12 Airfoil with a Variable Droop Leading Edge ...................................................................................................................................................................................... 96 P. Martin, K. McAlister, M. Chandrasekhara, W. Geissler Estimating Blade Section Airloads from Blade Leading-Edge Pressure Measurements............................................. 114 J. Aken Calculation of Rotor Performance and Loads Under Stalled Conditions..................................................................... 135 H. Yeo Aerodynamic Design of a New Affordable Main Rotor for the Apache Helicopter..................................................... 150 R. Ram, R. Smith, B. Charles, A. Hassan Effect of Airfoil Wall Temperature on the Performance of Micro-Rotorcraft............................................................. 167 J. Kim, N. Koratkar AERODYNAMICS II – COMPUTATIONAL FLUID DYNAMICS Analysis of Vorticity Confinement for Compressible Flows .......................................................................................... 178 M. Costes, G. Kowani Toward a Better Understanding of Ducted Rotor Antitorque and Directional Control in Forward Flight................................................................................................................................................................................... 191 E. Alpman, L. Long, B. Kothmann A Non-Linear Indicial Method for the Calculation of Unsteady Airloads.................................................................... 204 D. Lee, J. Leishman, J. Baeder Ice Accretion Computations for Full Tiltrotor Configurations ..................................................................................... 232 J. Narramore, P. Tran, G. Baruzzi, W. Habashi, I. Akel, S. Balage Simulation of Unsteady Rotor-Fuselage Interactions Using Unstructured Adaptive Meshes..................................... 240 Y. Park, H. Nam, O. Kwon Validation of UH-60A Rotor Blade Aerodynamic Characteristics Using CFD ............................................................ 251 J. Sitaraman, J. Baeder, I. Chopra Towards Affordable CFD Simulations of Rotors in Forward Flight -- A Feasibility Study with Future Application to Vibrational Analysis................................................................................................................................. 268 H. Ven, O. Boelens AERODYNAMICS III – WAKES AND VORTICES Predictions of Transient Rotor Wake Aerodynamics in Response to Time-Dependent Blade Pitch Inputs.................................................................................................................................................................................. 285 S. Ananthan, J. Leishman First-Principles Free-Vortex Wake Analysis for Helicopters and Tiltrotors................................................................ 307 D. Wachspress, T. Quackenbush, A. Boschitsch The Interdependence of Straining and Viscous Diffusion Effects on Vorticity in Rotor Flow Fields......................... 331 M. Ramasamy, J. Leishman Helicopter Rotor Response to Wake Encounters in Ground Effect .............................................................................. 346 G. Whitehouse, R. Brown Development of Unsteadiness in the Wake of a Rotor in Ground Effect ...................................................................... 362 T. Saijo, B. Ganesh, A. Huang, N. Komerath, S. Bhattacharya, D. Pulla, A. Conlisk AIRCRAFT DESIGN I Design & Development of a Thrust Augmented Entomopter: An Advanced Flapping Wing Micro Hovering Air Vehicle......................................................................................................................................................... 370 M. Tarascio, I. Chopra Development of an Advanced Singletilt Disc System VTOL Aircraft........................................................................... 388 S. Yassini, G. Syrovy Application of an Integrated Decision Support System for Mid-Life Upgrade of Helicopters ................................... 400 R. Kusumo, A. Sinha, D. Schrage Application of a Probabilistic Design Environment to the Mission Requirements and Technologies for a Heavy Lift Helicooper .................................................................................................................................................... 410 A. Baker, D. Mavris, D. Schrage Evaluation of Low Cost Unmanned Aerial Vehicle Comprised of Commercial-Off-The-Self Components as a Testbed for Military Research and Development.............................................................................. 420 T. Watson Jr. A Rapid Geometry Generator for Rotorcraft Exploratory Design with Computational Fluid Dynamics ............................................................................................................................................................................ 428 R. Narducci, J. Hirsh, T. Grandine, J. Vandenbrande, T. Hogan UNCONVENTIONAL VTOL AIRCRAFT DESIGN SPECIAL SESSION A Safe and Fuel-Efficient VTOL "Personal Aircraft" ................................................................................................... 438 K. Milde Jr., A. Pruszenski Jr., J. Wagner AIRCRAFT DESIGN II Lastest Developments in Fluidlastic® Lead-Lag Dampers for Vibration Control in Helicopters ............................... 446 P. Jones, D. Russell, D. McGuire Advanced Technologies for High Performance NH90 Blades........................................................................................ 456 P. Rauch, C. Quillien Design of New EUROCOPTER Medium Twin Helicopter EC145................................................................................ 468 A. Humpert High Stiffness ("Rigid") Helicopter Pylon Vibration Isolation Systems....................................................................... 485 D. McGuire Design of an Integrated Servo-Flap Main Rotor............................................................................................................. 495 F. Wei Composite Fuselage Design Synthesis.............................................................................................................................. 506 D. McCarthy, E. Walliser Modelling Dynamic Rollover and Related Lateral Responses ....................................................................................... 516 A. Cooke AVIONICS & SYSTEMS I Mobile Commander's Associate for AMUST-D.............................................................................................................. 551 P. Stiles, C. Bodenhorn, K. Galamback Comanche Situational Knowledge: A Consolidated Network View of the Battlefield: Maximizing the Versatility of the Tass Target Threat Manager..............................................................................................................