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3D Simulation Acoustics and
Vibration – Powertrain Seoul, Thursday April 2nd, 2015
2015-XX-XX
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Page 2 Siemens PLM Software
3D Simulation – What’s New on Acoustics and Vibration
Agenda
Introduction
Standard Solutions
Customization and Automation
1
3
4
Advanced Engineering Solutions 2
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Powertrain Noise
Fuel injection
Transmission
Turbo-charger
Air intake Exhaust Engine cooling
Alternator
Engine mechanical / combustion noise Fuel / Oil / water pump
Electric motor
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3D Simulation
Solutions at different levels
Standard Product Offering,
customization and related
deployment services
Engine radiation, Intake noise
Exhaust noise, Interior
Acoustics
Structural Engineers
Working on powertrain
programs
Standard Product Offering
Technology transfer for
specialized applications
Electric Motors, Injector Systems,
Engine cooling, Turbo-charger,…
NVH Engineers
Working on powertrain programs
Advanced Engineering
Projects with Subsequent
Product Offering
Example: Composites and
NVH, Lightweight gears
Focus on Advanced
Engineering, research
Long term horizon
2 1 3
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3D Simulation – What’s New on Acoustics and Vibration
Agenda
Introduction
Standard Solutions
Customization and Automation
1
3
4
Advanced Engineering Solutions 2
2015-XX-XX
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Advanced Engineering Projects: gear noise
Why gears are important?
They are used in pretty much every machine
They can cause vibrations, noise and can fail in operating conditions
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Gear modeling:
Applications
Gear Joint Semi-empirical Advanced FEA 3D contact
Low High Model complexity/fidelity
Kinematics System Level Operational conditions/High fidelity
Stress Gear pair
System Level Nominal conditions
Transmission
Gear pair
Transmission ratio, Power flow analysis, Efficiency, Shiftability
Durability, Root stress
Gear whine
Gear rattle, clunk noise
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Contact modeling
Contact modeling =
1. Detecting contact + computing amount of required deflection
+
2. Translate deflections into contact loads
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Detecting contact + computing amount of required
deflection
+ Efficient
- Only for gears, not for arbitrary shapes
(also feasible for bearings, cams, …)
‘Classical’ Unloaded Tooth Contact Analysis
Non-linear FE
Exploiting intrinsic geometric properties of gears
- ‘Brute force’ slow
+ Any geometry
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Gear modeling
Aspects of contact detection and its relevance
What? In-plane relative
translations
Axial relative
translation
Profile
modifications
Profile errors
Mesh phasing Rotational
misalignment
Flank line
modifications /
errors
Full topological
modifications /
errors
What is it
relevant for?
Backlash as
function of load
Frequency
sidebands due to
eccentricity
Gear rattle
(helical gears)
Gear whine
Frequency
sidebands due
to errors
‘Ghost’ noise
Planetary
transmissions
Twin
countershafts
Collector gear
System-level
dynamics
Gear whine
Tooth loading
Durability
Gear whine
Tooth loading
durability
RTD solver currently in
development
Standard
product
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Profile and indexing errors = deviation from involute due to manufacturing errors
Frequency
Gear
co
nta
ct
forc
e (
dB
)
Without indexing errors
With indexing errors sidebands appear
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Manufacturing and assembly errors:
Gear eccentricity
Gear eccentricity and run-out, microg-eometry errors, tooth spacing errors, …
give rise to frequency sidebands
E.g. Planetary transmission stage of automatic transmission
Sun eccentricity error
sidebands at multiples of ωsun – ωplanet carrier
Ring eccentricity error
sidebands at multiples of ωplanet carrier
Frequency
x
y
Rin
g-p
lan
et ge
ar
con
tact fo
rce [d
B]
GMF
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Contact modeling
Contact modeling =
1. Detecting contact + computing amount of required deflection
+
2. Translate deflections into contact loads
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Contact compliance modeling:
exploiting intrinsic physical properties
Away from contact Near contact
Geometry complex simple
Deformation gradients gentle strong
FE preprocessing analytical solution
= +
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Gear mesher/tooth stiffness calculation
Gear manufacturing plan
or Gear geometry
Gear FE mesh 2
Gear blank geometry
1
3
Gear blank compatible
mesh
4
Load cases and
boundary conditions*
5
NX NASTRAN SOL 101
6
Post-processing (xls)
7 LMS Virtual.Lab
Motion
8
4
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What can we capture:
Unique capability to predict NVH of lightweight gears
Frequency
Ge
ar
co
nta
ct
forc
e (
dB
)
L
S
Novel approach
Captures
frequency sidebands
Best possible
using
conventional
methods
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Dedicated Siemens PLM – Unical – KU Leuven gear test rig
Key features
• Gear sizing, loads and speeds correspond to
automotive applications
• Heavily instrumented
• Controllable misalignment and center distance
• Family of high-precision gears with various
microgeometry modifications
Angular
Parallel
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Correlation simulation –test rig (solid-disk spur
unmodified gears)
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Gear test rig and validation:
next steps
Helical gears Lightweight gears Offset web
Lightweight gears Holes without
integer multiplicity
Lightweight gears Holes with
integer multiplicity
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Transmission builder GUI
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Transmission builder GUI NX/Virtual.Lab
Virtual.Lab Motion NX CAE
Scripting / parametric CAD templates
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Gear Noise Simulation
Non-linear FE Conventional
MB technology
New VLMotion
Solution
Pre-processing computation N/A N/A 1 hr / flex gear
Solving days minutes minutes
Captures effect of holes in web?
System-level simulation?
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3D Simulation – What’s New on Acoustics and Vibration
Agenda
Introduction
Standard Solutions
Customization and Automation
1
3
4
Advanced Engineering Solutions 2
2015-XX-XX
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Prime needs
Max Boost!
THE primary reason for
the existence of the
turbocharger = boost
engine torque
Industry solutions:
• Variable turbine vane
geometry to optimize
compressor working point
of the turbo
• Tuning of inlet runners
after the compressor to
increase cylinder fill rates
Structure Borne
Whine
Housing and connected
ducts vibrate and
radiate sound
Industry solutions:
• Shaft Balancing and use
of floating bearings
• Modifications (stiffening)
of turbocharger housing
and of intake and
exhaust ducts
Air Borne
Pulsation Noise
The duct walls
between turbo and
intercooler are excited
by resonances
Industry solutions:
Resonators in the duct
between compressor and
intercooler take away
energy from the main
duct duct walls less
excited lowered
vibration and noise
Aero-Acoustic
Noise
Blow and Surge Noise (clearance) Hissing Noise (Wastegate) Buzz saw (supersonic blade tip speed)
Industry solutions:
Increase quality of
Manufacturing process to
reduce clearances and
avoid reversed flow
(surge)
Low Noise Emission During Operation
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LMS 3D Solutions
Structure Borne
Whine
Bearing loads are applied
to Virtual.Lab NVH for
vibration prediction.LMS
Virtual.Lab FEM
Acoustics with AML for
fast computation of
Acoustic Radiation
Air Borne
Pulsation Noise
LMS Virtual.Lab
(Coupled) FEM Vibro-
Acoustics to compute
Acoustic Power
Attenuation of
resonators (and radiated
acoustics from a
vibrating duct)
Fast Assessment
of Structural
Modifications
LMS Virtual.Lab NVH
Modification Prediction
enables making
elementary structural
changes
LMS Virtual.Lab 11
Acoustics’ Vibro-
Acoustic Structural
Solver allows assessing
effect of more in depth
design or material changes
Correlation
LMS Virtual.Lab
Correlation and
Updating enables to
increase the accuracy of
the structural FE Models
used for turbo-housing and
connected (rubber) hoses
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Noise attenuation of a turbocharger muffler system
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Powertrain Noise
Fuel injection
Transmission
Turbo-charger
Air intake Exhaust Engine cooling
Alternator
Engine mechanical / combustion noise Fuel / Oil / water pump
Electric motor
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Prime needs
Optimal Combustion
THE primary reason for the
existence of highly
responsive and accurate
injection systems = to
ensure good combustion
and optimal power output
Industry solutions:
• Piezo-stack injector
increases
responsiveness
• Common Fuel Rail kept
at 1500 bar and higher
for responsiveness and
good atomization of the
fuel
Low Force Excitation
of Injector House and
Cylinder Head
Contact of valves and
injector Needle when
slapping
against
injector
housing
Industry solutions:
• Design of Injector
Components
• Signal Design of
Injection Pulse(s):
Speed of Attack,
Sustain, Speed of
Release
Low Vibration of the
Fuel Rail / Hoses and
Cylinder Head
Forces act on injectors
which transfer energy to
fuel rail
and
cylinder
head
Industry solutions:
• Gasoline: O-ring defines
stiffness of coupling
between injector and
cylinder head
• Diesel: Fixed (rigid)
connection between
injector and cylinder
head
• Fuel Rail design for
sufficient stiffness
Low level of
propagated noise
Vibrations of the Fuel
Rail and Engine
Surfaces
Radiate
Noise
Industry solutions:
• Structural
modifications to
render cylinder
head and Fuel rail
more stiff on itself
and more isolated
from the injector
excitations
• Engine Bay Sound
Proofing
Low Noise Emission During Operation
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LMS 3D Solutions
LMS Imagine.Lab (AMESim)
1D model for piezo injector
Fast simulation of:
• detailed coupled electro-
hydro-mechanical injector
system
• with simplified modeling
for the (mechanical
cylinder head) boundary
condition
LMS Virtual.Lab Acoustics
3D structural-acoustical model
Coupled Vibro-Acoustic
Simulation:
• Requires fuel velocity
pulses and valve and
needle contact forces on
injector housing
• provides structural
vibrations in frequency and
time domain (IFFT)
High freq Sound Pressure
Response:
• Time Domain Analysis (TD
BEM)
• Frequency Domain Analysis
(new FEM solver with AML
perfectly matched layer)
LMS Virtual.Lab Acoustics
3D acoustical model
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Noise from Injector
Structural FE Model
1D Model
Injection System
Measurement
Uncoupled
Coupled (2% damp)
Coupled (0% damp)
Vibro-Acoustic Model
Source: “Driving NVH Refinement of Next Generation Powertrains through Virtual Design”,
Mario Felice, Ford, 2008 LMS Conference on Virtual and Physical Prototyping
2015-XX-XX
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3D Simulation – What’s New on Acoustics and Vibration
Agenda
Introduction
Standard Solutions
Customization and Automation
1
3
4
Advanced Engineering Solutions 2
2015-XX-XX
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Page 38 Siemens PLM Software
Typical picture at A-OEMs
For Engine Noise and Intake/Exhaust noise
Current situation
5 Virtual.Lab Acoustic seats
15 users worldwide (US, EMEA, China, Japan, Korea,..)
‘NVH Specialist users’
Working from a set of clear procedures
One simulation could take them ‘one full day’
Objective
Speeding up and Scaling up: how can one get much more, faster out of
simulation? How can we use Virtual.Lab Acoustics earlier in the development
process and to be used by many more, non-specialist engineers?
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Virtual.Lab Acoustics for Engine/Intake Noise
Project with major OEM
• Customization on top of Virtual.Lab
Packaged with LMS Virtual.Lab
• Adding Value and Reducing Cost
• Users focus on value-add analysis
resulting in higher quality products
• 1Day user work is reduced to 30min,
significantly reducing costs.
• Novice, non-expert users do perform
powertrain noise analyses. Growing
from 15 to 30 regular users.
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Virtual.Lab Acoustics for Powertrain Noise
• Easy to Use Black Box
• Aligned exactly with OEM Process
• Embedded User Help
• Drive Via .Txt
• Drive Via GUI
• Status Ribbon
• Run Local or on Cluster (NIC)
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Application 1: Powertrain Radiation
• Dedicated GUI
• Fully controlling LMS Virtual Lab
Acoustics
• Virtual.Lab completely running in
batch
• Choice of input GUI Fields or .txt
template
• Intuitive design:
• Tab 1: Structural: (surface
velocities)
• Tab 2: Acoustic ATV Analysis
• Tab 3: Acoustic ATV Response
• Tab 4: Post Processing
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Application 2: Acoustics Vector Processing Case
• Dedicated GUI
• Fully controlling LMS Virtual Lab
Acoustics
• Virtual.Lab completely running in
batch
• Choice of input Fields or .txt
template
• Intuitive design:
• Tab1: Structural: (surface
velocities)
• Tab2: Post Processing
• Number of critical RPMs
• Number of Peaks
• Octave selection
• Sum options
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Application 3: Acoustics Post Processing
• Post Processing: Clean and Easy : all
automatic, NO SINGLE user
interaction
• Creation of MS PowerPoint
• Plot generation
• Auto peak selection
• Corresponding contour image creation
• Articulation Index (AI)
• Subfolder file organization (Searchable)
• Data dumping to Excel
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Powertrain Acoust
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LMS Virtual Lab Acoustics
Automation = Scalability