Fuselage Excitation During Cruise Flight Conditions: From Flight Test to Numerical Prediction
Alexander Klabes1, Sören Callsen2, Michaela Herr1, Christina Appel11German Aerospace Center2Airbus Operations GmbH
FLINOVIA IIApril 27-28, 2017Penn-State University
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 1
Overview
• Introduction
• Flight test data overview
• Literature TBL prediction models
• CFD calculation and analysis
• New CFD and CAA based TBL prediction models
• Coupling TBL models with SEA
• Results & Outlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 2
Overview
• Introduction
• Flight test data overview
• Literature TBL prediction models
• CFD calculation and analysis
• New CFD and CAA based TBL prediction models
• Coupling TBL models with SEA
• Results & Outlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 3
Introduction
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 4
Excitation & Coupling
Impo
rtan
ce o
f sou
rces
+
-TBL*
Cabin Noise Sources
*Turbulent Boundary Layer
Introduction
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 5
TBL
Development of models for EXCITATION:
1. Auto-spectra prediction2. Wavenumber-freq. spectra prediction
based on flight test data and numericalmethods (CFD & CAA), and
3. Investigation of COUPLING methods4. Calculation of structural vibration Statistic Energy Analysis
Impo
rtan
ce o
f sou
rces
+
-
Excitation & Coupling
Cabin Noise Sources
Overview
• Introduction
• Flight test data overview
• Literature TBL prediction models
• CFD calculation and analysis
• New CFD and CAA based TBL prediction models
• Coupling TBL models with SEA
• Results & Outlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 6
Flight test data overviewSensors
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KulitePressure Transducers
PCBAccelerometers
Brüel & KjaerSurface Microphones
Flight test data overviewAnalysis
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 8
Flight test data overviewValidation Auto-Spectra
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 9
Overview
• Introduction
• Flight test data overview
• Literature TBL prediction models
• CFD calculation and analysis
• New CFD and CAA based TBL prediction models
• Coupling TBL models with SEA
• Results & Outlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 10
Literature TBL prediction modelsAuto-Spectra
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 11
Family 1
Family 2
FL350, Ma 0.78 FL350, Ma 0.78
Literature TBL prediction modelsWavenumber-Frequency Spectra
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 12
RhombicModels
(Corcos)
EllipticalModels(Chase)
Overview
• Introduction
• Flight test data overview
• Literature TBL prediction models
• CFD calculation and analysis
• New CFD and CAA based TBL prediction models
• Coupling TBL models with SEA
• Results & Outlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 13
CFD calculation and analysis
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 14
RANS (TAU) simulation with RSMg turbulence model of a detailed geometry, including HTP, VTP and clean wings
Flight level TAS [m/s] AoA [°]
310 234 1
245 0.9
350 237 2
247 2, 3, 4
390 234 2.7
245 2.7 • Cube dominated SOLAR-grid• 1. wall distance 0.0067 mm • 51 points in TBL• y+ at fuselage 0.3• Stretching factor 1.2
CFD calculation and analysis
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 15
• Focus is on the analysis of:
• Pressure coefficient • Local boundary layer thickness• Local edge velocities• Local flow directions• Turbulence kinetic energy• And further parameters, which are important for the auto-spectra models
• Boundary layer thickness as well as the local flowdirection is validated by in-flight measured data
Overview
• Introduction
• Flight test data overview
• Literature TBL prediction models
• CFD calculation and analysis
• New CFD and CAA based TBL prediction models
• Coupling TBL models with SEA
• Results & Outlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 16
New CFD and CAA based TBL prediction models
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 17
Semi-empiricalapproach
Numericalapproach
Auto-spectrummodel
Auto-spectrum Wavenumber-freq. spectrum
CFD Goody model CFD FRPM*
*Fast Random Particle-Mesh Method
Auto-spectrum
+ +
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 18
New CFD and CAA based TBL prediction modelsNumerical approach
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 19
kx
ky
Overview
• Introduction
• Flight test data overview
• Literature TBL prediction models
• CFD calculation and analysis
• New CFD and CAA based TBL prediction models
• Coupling TBL models with SEA
• Results & Outlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 20
Grahams method
Coupling TBL models with SEA
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 21
VA 1
Wavenumber-freq. spectraAuto-spectra
Sorts the energy of turbulence into
frequencies
Information about space & time
development of turbulence
Calculates the coupling of TBL & fuselage structure Structural vibration
kx
ky
Overview
• Introduction
• Flight test data overview
• Literature TBL prediction models
• CFD calculation and analysis
• New CFD and CAA based TBL prediction models
• Coupling TBL models with SEA
• Results & Outlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 22
Results & OutlookA320
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 23
SubsystemRoof
Constant Auto-Spectrum model
Results & OutlookA320
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 24
SubsystemRoof
Constant Auto-Spectrum model
Results & OutlookSummary
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 25
• Unique data base of in-flight measured TBL excitation in cruise flight conditions
• CFD calculations with TAU for A320 in cruise flight conditions (similar to flight tests)
• Semi-empirical auto-spectrum model adapted to measurements and based on CFD data, by including turbulence kinetic energy, pressure gradient…
• Full numerical approach to calculate auto-spectra as well as wavenumber-frequency spectra
• Testing of different literature wavenumber-frequency models
• Calculation of structural vibration with Grahams method and SEA for a flat plate
• Calculation of structural vibration of an Airbus A320 and validation with measured structural acceleration
Results & OutlookOutlook
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 26
• Further developing of the auto-spectrum model towards higher pressure gradients in the cockpit region
• Further testing of numerical methods in high pressure gradient areas
• Application of methods to the whole Airbus aircraft family
> FLINOVIA II > Alexander Klabes > April 27-28, 2017DLR.de • Chart 27
Thank you for your attention