ADYN ADVANCED EUROPEAN TILTROTOR DYNAMICS AND NOISE NUMERICAL - PowerPoint PPT Presentation

ADYN ADVANCED EUROPEAN TILTROTOR DYNAMICS AND NOISE NUMERICAL WHIRL-FLUTTER INVESTIGATION OF THE EUROPEAN TILTROTOR CONCEPT: CURRENT STATUS AND FUTURE PROSPECTS Dr. Pierangelo MASARATI Dipartimento di Ingnegneria Aerospaziale Politecnico di Milano 30 th European Rotorcraft Forum Marseille, France September 14-16, 2004 Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 1 14-16 September 2004

Consortium & Acknowledgments Emanuele Bianchi Mauro Frosoni Agusta (I) IDS (I) Anselmo Russo Richard Bakker CIRA (I) NLR (NL) Fritz Kießling Vasilis Riziotis DLR (D) NTUA (GR) Rogelio Ferrer Didier Petot Eurocopter (F) ONERA (F) Oliver Dieterich Massimiliano Lanz Eurocopter (D) POLIMI (I) Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 2 14-16 September 2004

EUROPEAN TILTROTOR CONCEPT Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 3 14-16 September 2004

� � EUROPEAN TILTROTOR CONCEPT Nacelle tilting interconnected Outer portions of wing independently tiltable Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 4 14-16 September 2004

ADYN description WP1 Whirl-Flutter: Requirements and Preliminary Calculations Numerical simulation of tiltrotor whirl flutter behaviour Investigation on major design parameters Wind tunnel model requirements WP2 Whirl-Flutter: Model Preparation and Test Design and manufacture of a Dynamically-scaled half-span WT model Test campaign in a high speed WT Validation of computational tools with experimental database WP3 Aeroacoustic Assessment and Optimisation WT tests of TILTAERO’ s rotor to explore its noise characteristics Design and manufacture of a new blade with improved noise characteristics WT tests of the new blades Validation of computational tools with experimental database WP4 High-Speed Performance Assessment WT tests of rotors to measure and validate the performances Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 5 14-16 September 2004

� � � � � ADYN description Enhance the EU knowledge on tiltrotor technologies by deeply analyzing whirl-flutter Comparison of analytical and experimental results Tests of a half-span scaled model in high speed wind tunnel facilities The wind tunnel model will help optimize rotor blade design for low external noise The project will provide final recommendations for the design of a full-scale tiltrotor flight demonstrator (European Tiltrotor Concept) Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 6 14-16 September 2004

WP1 Whirl Flutter Task Objectives & Organization WP 1: Whirl Flutter: Requirements & Preliminary Calculations T 1.1: Mathematical models ST 1.1.1: Preliminary WF and dynamic behavior prediction (C) ST 1.1.2: WT model stability and WF prediction (C) ST 1.1.3: Analysis of special aspects regarding WF (A) ST 1.1.4: WT model update and prediction of WF boundary (F) T 1.2: Establishment of model requirements & variants to TILTAERO WP 2: Whirl Flutter Model Preparation & Test Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 7 14-16 September 2004

Software Tools Partner Software Developed by Type CIRA CIRANO CIRA MB DLR NASTRAN + ZAERO* Commercial FEM EC HOST EUROCOPTER Comp. ECD CAMRAD II Commercial Comp./MB IDS CAMRAD JA + NASTRAN Commercial Comp. + FEM NLR Flightlab Commercial Comp./MB NTUA GAST NTUA MB ONERA HOST EUROCOPTER Comp. POLIMI DYMORE GaTech/POLIMI MB MBDyn ( + NASTRAN) POLIMI MB ( + FEM) * Fixed wing only Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 8 14-16 September 2004

Wing Design movable wing actuators tube/nacelle actuator tube supports nacelle movable wing fixed wing tube (outboard) wing-fuselage tube (inboard) connection Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 9 14-16 September 2004

Wind Tunnel Model: Overview Windmilling Dynamically Rotor Scaled Wing DNW Closed Reflection Section Floor Plane Model Support Structure Fairing Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 10 14-16 September 2004

Wind Tunnel Model: Nacelle Details Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 11 14-16 September 2004

Wind Tunnel Model Support WT closed section floor turn table wind direction Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 12 14-16 September 2004

Numerical Model of the Rotor Hub Single load path Multiple load path beam rigid Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 13 14-16 September 2004

Excitation System Mass Summary: Motor: 1.3 Kg/motor Frames (aluminum): 8.6 Kg Attachments: 1.8 Kg Max. rotating masses: 1.6 Kg/motor Total mass (max including frames): 16.6 Kg Excitation forces: Max Flap excitation @ 6 Hz 150 N/motor 300 N Max Torsion excitation @ 12 Hz 600 N/motor 360 Nm F 1 F Cres 2 Unbalanced Unbalanced mass mass Motor 2 Motor 1 2 counterrotating motors 2 motors rotating in phase with masses at 0 deg: with masses at 180 deg: beamwise excitation torsion excitation Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 14 14-16 September 2004

Excitation System (Cont.) Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 15 14-16 September 2004

Analyzed Configurations Wing Blades Hub Nacelle 1 Full-scale European Tiltrotor Concept (ETRC) 2 Mach-scale ETRC 3 Mach-scale ETRC TILTAERO 4 Mach-scale ETRC TILTAERO ADYN 5 ADYN TILTAERO ADYN ADYN (overweight) Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 16 14-16 September 2004

Whirl-Flutter Stability Results 50 1 0.8 40 0.6 Frequency - Hz 30 Damping 0.4 20 0.2 10 0 0 -0.2 0 100 200 300 400 500 0 100 200 300 400 500 Flight Speed - KTAS Flight Speed - KTAS Mach-scale: critical mode is wing beam Figure 1: Whirl flutter Mach scaled nacelle: critical mode: wing vertical bending (green) 50 1 0.8 40 0.6 Frequency - Hz 30 Damping 0.4 20 0.2 10 0 0 -0.2 0 100 200 300 400 500 0 100 200 300 400 500 Flight Speed - KTAS Flight Speed - KTAS Overweight nacelle: critical mode becomes wing torsion Figure 2: Whirl flutter overweight nacelle: critical mode: wing torsion (grey) Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 17 14-16 September 2004

� � � � � Model Design Issues Nacelle/hub mass is larger than Mach-scale Tailoring of the whirl-flutter mode to be wing beam Tailoring of the wing beam mode damping Wing will be stiffer than Mach-scale Kinematic/constitutive couplings are being investigated Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 18 14-16 September 2004

� � � � Future Work There are delays partially related to sibling projects Whirl-flutter tests in late 2005 in DNW (Marknesse) High-speed tests in early 2006 at ONERA (Modane) WP1/2 (and ADYN as a whole) is expected to proceed without further delays Marseille, France, WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 19 14-16 September 2004