Post on 02-Feb-2022
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 1
ADYNADVANCED EUROPEAN TILTROTOR
DYNAMICS AND NOISE
Dr. Pierangelo MASARATI
Dipartimento di Ingnegneria AerospazialePolitecnico di Milano
30th European Rotorcraft ForumMarseille, France
September 14-16, 2004
NUMERICAL WHIRL-FLUTTER INVESTIGATIONOF THE EUROPEAN TILTROTOR CONCEPT:
CURRENT STATUS AND FUTURE PROSPECTS
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 2
Emanuele BianchiAgusta (I)
Anselmo RussoCIRA (I)
Fritz KießlingDLR (D)
Rogelio FerrerEurocopter (F)
Oliver DieterichEurocopter (D)
Consortium & Acknowledgments
Mauro FrosoniIDS (I)
Richard BakkerNLR (NL)
Vasilis RiziotisNTUA (GR)
Didier PetotONERA (F)
Massimiliano LanzPOLIMI (I)
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 3
EUROPEAN TILTROTOR CONCEPT
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 4
EUROPEAN TILTROTOR CONCEPT
� Nacelle tilting interconnected
� Outer portions of wing independently tiltable
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 5
ADYN description
WP1 Whirl-Flutter: Requirements and Preliminary CalculationsNumerical simulation of tiltrotor whirl flutter behaviourInvestigation on major design parameters Wind tunnel model requirements
WP2 Whirl-Flutter: Model Preparation and TestDesign and manufacture of a Dynamically-scaled half-span WT model Test campaign in a high speed WTValidation of computational tools with experimental database
WP3 Aeroacoustic Assessment and OptimisationWT tests of TILTAERO’ s rotor to explore its noise characteristicsDesign and manufacture of a new blade with improved noise characteristicsWT tests of the new blades Validation of computational tools with experimental database
WP4 High-Speed Performance AssessmentWT tests of rotors to measure and validate the performances
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 6
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,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 7
WP1 Whirl Flutter Task Objectives & Organization
WP 1: Whirl Flutter: Requirements & Preliminary Calculations
T 1.1: Mathematical modelsST 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,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 8
Software Tools
Partner Software Developed by Type
CIRA CIRANO CIRA MBDLR NASTRAN + ZAERO* Commercial FEMEC HOST EUROCOPTER Comp.ECD CAMRAD II Commercial Comp./MBIDS CAMRAD JA + NASTRAN Commercial Comp. + FEMNLR Flightlab Commercial Comp./MBNTUA GAST NTUA MBONERA HOST EUROCOPTER Comp.POLIMI DYMORE GaTech/POLIMI MB
MBDyn ( + NASTRAN) POLIMI MB ( + FEM)* Fixed wing only
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 9
Wing Design
movable wing actuators tube supports tube/nacelle actuator
nacelle
tube (outboard)movable wing fixed wing
tube (inboard)wing-fuselage connection
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 10
Wind Tunnel Model: Overview
Reflection Plane
DNW Closed Section Floor
Model Support Structure Fairing
Windmilling Rotor
Dynamically Scaled Wing
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Wind Tunnel Model: Nacelle Details
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 12
Wind Tunnel Model Support
WT closed section floor
turn table
wind direction
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Numerical Model of the Rotor Hub
Multiple load path
Single load path
beamrigid
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Excitation System
Unbalanced mass
Motor 1Motor 2
Unbalanced mass
F1F2 Cres
2 counterrotating motorswith masses at 0 deg:beamwise excitation
Mass Summary:Motor: 1.3 Kg/motor Frames (aluminum):
8.6 KgAttachments: 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 NMax Torsion excitation @ 12 Hz 600 N/motor 360 Nm
2 motors rotating in phasewith masses at 180 deg:
torsion excitation
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 15
Excitation System (Cont.)
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 16
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,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 17
Whirl-Flutter Stability Results
Flight Speed - KTAS
Fre
quen
cy-H
z
0 100 200 300 400 5000
10
20
30
40
50
Elastic Rotor 1.0: Whirl Flutter
Flight Speed - KTAS
Dam
ping
0 100 200 300 400 500-0.2
0
0.2
0.4
0.6
0.8
1
Elastic Rotor 1.0: Whirl Flutter
Figure 1: Whirl flutter Mach scaled nacelle: critical mode: wing vertical bending (green)
Flight Speed - KTAS
Fre
quen
cy-
Hz
0 100 200 300 400 5000
10
20
30
40
50
Elastic Rotor 1.0: Whirl Flutter (Nacelle Overweight)
Flight Speed - KTAS
Dam
ping
0 100 200 300 400 500-0.2
0
0.2
0.4
0.6
0.8
1
Elastic Rotor 1.0: Whirl Flutter (Nacelle Overweight)
Figure 2: Whirl flutter overweight nacelle: critical mode: wing torsion (grey)
Mach-scale: critical mode is wing beam
Overweight nacelle: critical mode becomes wing torsion
Marseille, France,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 18
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,14-16 September 2004 WP1: NUMERICAL WHIRL-FLUTTER INVESTIGATION 19
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