acoustic cae in japan automotive) applications...acoustic cae in japan ... by msc nastran) ......
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Table of Contents
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ACTRAN OVERVIEW
FREQUENCY DOMAIN AND TIME DOMAIN.
CO-SIMULATION
ACOUSTIC APPLICATION
Frequency Domain and Time Domain
• Actran:Aciustic CAE
• Vibro-Acoustic
• Aero-Acoustic
• Frequency Domain
is usual.
• Japanese customers
are interested in time
domain analysis.
Example: Co-Simulation(Gear Noise)
MBD & FEA
coupled simulationsMBD Results Acoustic Analysis
Rigid parts Motion Create MNF (powered
by MSC Nastran) …
Export Flex parts vibrations in OP2 file format
Acoustic analysis set-up Time-domain acoustic radiation Post processing:
• Acoustic maps, animations• Audio files• Frequency domain post-processin
g
Adams User Interface Actran VI
Example: Co-Simulation(Impact Sound for Golf Club)
• Adams• Model
• Head: Flexible `Part
• Shaft:Discrete Flexible Link
• Contact: Impact Function
• Analysis
• Total Time:0.5Sec
• Time Step :5e-5Sec
Flex(MNF)
DiscreteFlexibleLink
Adams Model
Example: Co-Simulation(Impact Sound for Golf Club)
• Actran• Analysis
• Total Time:0.5Sec
• Time Step :5e-5Sec
• Post Processing
• Subjective Evaluation
• WAVE File for results
• Sound Quality
• Objectivity evaluation
• 3D Map(Time vs Frequency vs
SPL)
Example: Co-Simulation(Sloshing Noise)
• What: Native interface with MSC Dytran (explicit solver for dynamic analysis, including FSI) time for performing acoustic radiation with Actran
• Targets: Fuel tank sloshing noise, hydraulic pipe noise, impact noise and others
• Key Benefit: Actran can read directly native MSC Dytran results in THS format
SAE 2015 World Congress & Exhibition, Complete Multi-Discipline Simulation for SloshingNoise. Douglas Marriott, Takeshi Ohtomo, Tohru Wako
Actran User in Japan
• Total 130
Actran User in Japan
Auto Auto Supplier
Electric Other Machinery
Aero University/ Research
Radiation Noise(Frequency Response)
Basic Acoustic Application
One way coupling (Vibration is calculated by other CAE tool)
Advantage of Actran
VI Mesher (Hexa Core)
Automatic Model Preparation(for Each Frequency)
Faster Analysis(Green Analysis)
Excellent Post Processing
Current Trend
Detailed Modeling
High Frequency
Electric Device Noise
Radiation Noise from Powertrain
• Good Correlation with Test Results
• High Speed Calculation (Green Analysis)
Test
CAE
Acoustic Radiation with ActranIntake Vibration with Nastran
Design Improvement – SPL Reduction
JMAG-Nastran-Actran
Electromagnetic force distribution
Mode Analysis
Acceleration
(JMAG)
(MSC Nastran)
(Actran)
1
2
3
出典:JMAG アプリケーションカタログ20番の事例
Acoustic
MSC Nastran(Mode Analysis)2
Mode No Frequency Hz
1 1760
2 1770
3 3670
4 4530
5 4790
6 4920
7 5930
1st Mode(1760 Hz)
5th Mode(4790 Hz)
Duct Noise Analysis
Duct and Silencer Application
Pipe Noise and Shell Noise
Advantage of Actran
VI Mesher (Hexa Core)
Automatic Model Preparation(for Each Frequency)
Modeling of Absorption:
Modeling of Pinching Metal
Temperature and Flow
TMM Analysis (Transfer Matrix Method)
Current Trend
Detailed Modeling
High Frequency
Remark for Vibro-Acoustic
On the complete line:The new advance TMM method is valid
even at high frequency
pressure at 5100Hz
Intake and Exhaust noise analysis
• Exhaust Noise• Pipe noise::
Flow・Temperature・Absorption
Punching Metal etc
• Shell noise:
Vibro-Acoustic
• Actran can consider• Duct Mode
• Temperature/Flow
• Absorption Punching Metal, …
• Strong Coupling with Vibration
• TMM
• Integration with 1D Tool
• Vehicle Design
エアークリナー内 マイク1
0
20
40
60
80
100
120
0 500 1000 1500
周波数(hz)
SPL(dB
)
simulation modified micro 1inside [SPL] SPL (in A/C 1)
Car Outside Noise Analysis
• Engine Noise
• Exhaust Noise
• Wind Noise
Exhaust noise
Input force from Engine
Booming n
oise
Sound quality
Frequency [Hz]En
gin
e r
evo
luti
on
s p
er
min
ute
[rp
m]
Transfer function for air-borne noise
Transfer function for structure-borne noise
Trim(Absorption) Analysis
Most Important Technology for Noise Reduction
Advantage of Actran
BIOT Model (UP: Detail setting)
BIOT Model (MIKI: Simple setting)
Impedance(without BIOT parameter)
Optimization of Parameters
Current Trend
Detailed Modeling
High Frequency
Remark for Vibro-Acoustic
Trimmed Body Analysis
W/o insulator
W/ insulator
Acoustic transfer function
Structure transfer function
Experiment
W/o insulator
W/ insulator
Acoustic transfer function
Structure transfer function
Dash insulator and floor carpet
Simulation
Rode Noise Analysis
• Two noise source are considered
• Structural Born Noise (Dynamic Load)
• Air Born Noise(DSF)
TL( Transmission Loss) Analysis
Most Important Technology for Noise Reduction
Advantage of Actran
DSF( Diffuse Sound Fields ) Boundary Condition
BIOT Model
Structural Born and Air Born
Current Trend
Experiment to CAE
TL Analysis(Glass with Rubber)
TL Champ Diffus
15
20
25
30
35
40
45
50
100 1000 10000
Frequency (Hz)
TL
(d
B)
Coulisse B9 P3 Initiale
Coulisse B9 P3 Géométrie n°1
Coulisse B9 P3 Géométrie n°2
Coulisse B9 P3 Géométrie n°3
Épaisseur de vitrage de 3,85 mm
Vibro-acoustic model
glass run c
hannel glass
air (I-FEM)
Non-Linear FE
Acoustic Analysis
Aero-Acoustic Analysis
Noise based on Aero-Dynamics
Integration with CFD tool
Advantage of Actran
Realistic Noise Source(Lighthill source/Mohring Source/Surface Pressure)
Many Experiences (Since 1998)
Filtering Technique for High Wave Number Source(Acoustic Perturbation Equation/Wave Number Decomposition /Pelliculer Decomposition)
Current Trend
Increase of the Demand
Aero-Vibro-Acoustic
Wind Noise with the SNGR Method
Challenge
Turbulences due to the wind flow around the car produce noise that can propagate inside the cabin. For pre-designing efficiently aerodynamic components it is necessary to speed the simulation process.
MSC Solutions
Actran is used to perform aeroacoustics computations with the SNGR method and Lightill sources. The pressure on the window coming from acoustic phenomenon hasbeen retrieved thanks to the wave numberanalysis.
Value
The SNGR method in Actran is validated by Mitsubishi motors. It uses only a steadyRANS CFD: it opens the door to predict efficiently the impact of an aerodynamic design on the acoustic transparency of windows.
Aerodynamic noise at 100km/h, 500Hzpressure 5dB lower on the rear wheel than on the front wheel
5m
microphone
Simulation vs. measurement
FFT Acoustic Simulation Conference 2014, Fumihiko Kosaka, MITSUBISHI MOTORS CORPORATION
Speaker Analysis
Most Popular Sound Analysis
Advantage of Actran
Coupling and Non-Coupling Analysis
Frequency Domain and Time Domain
Excellent Post Processing
Current Trend
Detailed Modeling
High Frequency
Sound Quality
Car Audio Speaker
PhysicalLoudspeaker & Acoustic
ModalCar door structure
Excitation Loudspe
aker configuration with T&S parameters
BEGIN MATERIAL 1VOICE_COILFORCE_FACTOR { 5.45, 0}ELECTRICAL_INDUCTANCE 0.00025ELECTRICAL_RESISTANCE { 2.6, 0}
END MATERIAL 1
Loudspeaker Equivalent Electric Circuit
Car inner cavity with/without acoustic treatment
• Volume 2.95m³
•𝐿
𝜆≈ 80
• Two Nvidia Tesla K80
• Frequency 15 kHz
• DOF 383 Million
• Computation time 4h00
Untreated Treated
Velocity BC / Loudspeaker
Impedance BC
Time Domain Analysis
Considering Non-Linear Phenomena
One way coupling and Vibro-Acoustic Coupling
Advantage of Actran
Stable for Large Scale Model
Sound Quality
Integration with Adams, Marc, Sol700,Dytran
Current Trend
Non-Linear Phenomena
Real Sound
Sound Quality
Time Domain Analysis(DGM)
Very Large Scale Acoustic Analysis(Ex. 1Billoin DOF)
Time Domain Analysis (Frequency response using Post Processing)
Advantage of Actran
New Methodology(Discontinuous Galerkin Method)
(Max) 16th Element Order
・Integration with Adams, Marc, Sol700,Dytran Sound Quality
Current Trend
High Frequency(Supersonic Wave Field)
Car Parking Sensor, Ultra Sound 50 kHz
• Two Nvidia Tesla K80• Frequency 50 kHz• DOF 984 Million• Simulation time14h40
• Volume 0.1 m³
•𝐿
𝜆≈ 135
Actran:Integration with many CAE tools
Acoustic
MBDLinear
Non-Linear
Pre/Post
SOL700
Aero Acoustic
Sound from Non-Linear FE
Sound from Non-Linear FE
Electro Magnetic
Pre/PostSound from Electro
Magnetic
Sound from Linear FE
Sound from MBD