ANSYS Multiphysics 8.0 Technology Overview & Benefits

Multiphysics 8.0 Customer 3.0- 1/30/04

1

Dr. Paul Lethbridge - Product Manager

ANSYS Multiphysics 8.0Technology Overview & Benefits

ANSYS Multiphysics 8.0Technology Overview & Benefits


2Topics Covered

• What is Multiphysics?

• Multiphysics Benefits

• Educational Products

• Market Applications

– Market segments by Technology

– Market Segments by Industry

• Multi Field (Coupled Physics) Capabilities

• Direct physics coupling

• Sequential physics coupling

• Multi-field Solver (New feature at release 8.0)

• Other New features

• Enhanced non-linear Piezoelectric & piezoresistive element.

• Fluid damping elements

• Cyclic Symmetry for Magnetostatics

• Low Frequency Electromagnetic Contact

• Coupled E-B Particle Tracing

• Re-meshing for FSI

• Selected Multi-Physics Examples

• Product Roadmap & Strategy

– Transition to Workbench Environment

• Product Websites























3The ANSYS Family of Products

Educational/Non Commercial Use Products

Ease of use &Entry level capability

Powerful tools for the physics specialist

High performance mechanical & Thermal

Extreme functionalityThe whole enchilada!ANANSYSSYS MultiphysicsMultiphysics

ANANSYSSYS MechanicalMechanical

ANANSYSSYS FLOTRANFLOTRAN

ANANSYSSYS EmagEmag

ANANSYSSYS ProfessionalProfessional

ANANSYSSYS Structural Structural

ANANSYS SYS MCAD & ECAD Connection productsMCAD & ECAD Connection productsANANSYS SYS MCAD & ECAD Connection productsMCAD & ECAD Connection products

ANANSYSSYS UniversityUniversity


4Topics Covered












































5

What is ANSYS Multiphysics?

Structural

Fluid Thermal

Electrostatic

Electrical

MagneticElectro-

magnetic

A general purpose analysis tool allowing a user to to combine the effects of two or more different, yet interrelated physics, within one, unified simulation environment.


6Benefits of Multiphysics

• No other analysis tool provides as many physics under one roof!

• Greatest breadth and technical depth of physics.

• Fully parametric models across physics, geometry, materials, loads.

• Perform Design Optimization across physics, geometry, materials and loads.

• Seamless integration with ANSYS Probabilistic Design System (PDS).

• Extremely sophisticated analysis capability.

• Bottom line benefits:

– Analysis closely match reality – bringing reality to the desktop

– Reduced assumptions that question certainty and compromise accuracy.

– Lower cost: Fewer analysis software tools to purchase,learn & manage.

– Lower cost: R&D process compression


7Benefits of Multiphysics

“The use of Multiphysics allows us to return to the basics of engineering where a model and the predictive solution closely approximate reality; this allows the engineer to design with a high degree of confidence that the answers are correct.”

Dr. Howard Crabb - Ford Motor Company


9 Educational Products – Problem Size Limits


10Topics Covered












































11

• Induction heating

• RF Heating

• Heat-exchangers

–Electronics cooling

–Automotive

–A/C systems

• SEMICON

–Ion implanters

–PVD / CVD

• Fluid systems

–Hydraulic

–Pneumatic

–Fuel

–Microfluidics

• Electromagnetic machines

–Pumps

–Generators

–Motors

–Solenoids

• Inertial

• Pressure

• Mass

• Proximity

• Thermal

• Acoustic

Market Applications by Technology

Sensors & Transducers Actuators Processes

Three “broad” Market segments uniquely identified as being inherently Multiphysics

Click mouse to progress


12Market Applications by Industry

• Electronics

• Automotive

• Aerospace / Space

• Marine

• SEMICON

• Government / Military

• Medical / BioMed

• Pharmaceutical

• Appliances

• Electronics

• Automotive

• Aerospace / Space

• Marine

• SEMICON

• Government / Military

• Medical / BioMed

• Pharmaceutical

• Appliances

Multiphysics is not limited to any specific industry.There are analysis applications and opportunity across the board.


13Topics Covered












































14Coupled Physics Capabilities: Methods

• There are two methods to couple physics, Direct & Sequential.

• Direct - solves all DOF’s at the FEA coefficient matrix level.

• Sequential - solves DOF’s for one physics then passes results as loads & boundary conditions to the second physics. At least two iterations, one for each physics, in sequence, are needed to achieve a coupled response.

• There are many confusing terms for the two methods:

Coupled Physics Terminology

Preferred ANSYS Inc. “descriptive usage”

Direct Sequential

Strict Mathematical usage

Matrix Load vector

LHS RHS

Monolithic Staggered

Archaic

Use at your peril!

Strong Weak

Tight Loose

Full Partial


15Direct Coupled Physics Applications

Coupled Physics Applications

Thermal-StructuralAnything with a structure!

Gas turbines.

Pressure-Structural (Inviscid FSI) Acoustics, sonar, SAW

Piezoelectric Microphones, sensors

Piezoresistive Pressure sensors, strain gauges, Accelerometers

Circuit coupled electromagnetics:

CIRCUIT124

CIRCUIT125

Motors, MEMS

Electrostatic- Structural:

TRANS126

TRANS109MEMS

Electro-thermal-structural -magnetic:

SOLID5, PLANE13

SOLID62, SOLID98IC, PCB electro-thermal stress, MEMS actuators

Fluid-thermal Piping networks, manifolds


16Sequential Coupled Physics Applications

Thermal-StructuralAnything with a structure!

Gas turbines.

Electromagnetic-thermal

Electromagnetic-thermal-structuralInduction heating, RF heating

Electrostatic-Structural

Electrostatic-Structural-Fluidic MEMS

Electrostatic – Charged particleIon Optics, Field Emission Display Technology,

Analytical instruments

Magnetic - Structural Solenoids, electromagnetic machines

Fluid-Solid:

FLOTRAN based FSI

MpCCI: Bi-directional FSI

CFX-ANSYS unidirectional interface

Aerospace, automotive fuel, hydraulic systems, fluid bearing,

MEMS fluid damping, drug delivery pumps, heart valves.

Electromagnetic-Solid-Fluid Fluid handling systems, EFI, hydraulic systems

Thermal-CFD Electronics cooling

Multi-field Solver Many! All of the above!

Sigfit: Unidirectional, Structural – Optical Automotive lighting, astronomy, any optical instruments


17Topics Covered












































18Multi-field Solver - Pretext

Situation Prior to Release 8.0:

• Significant number of multi-physics problems can be addressed with sequential coupling using core elements.

• Our current tools for sequential coupling require advanced APDL and domain knowledge to process solution.

• We have out-grown custom-command macros that perform sequential coupling e.g..:

–FSSOLV

–ESSOLV

• Fluid Solid Interaction (FSI) was a first step towards automated sequential coupling technology


19Multi-field Solver – Why?

There is Growing Market Requirement to:

• Solve multi-physics problems from all industries.

• Often need to incorporate more than two physics.

• Couple more easily to external codes

• Provide an easier to use Multiphysics environment for current analysts.

In Response:

ANSYS have developed a “multi-field” solver to automate sequential coupling, and be general enough in the design for

most multi-field solution requirements”

• The multi-field solver is an evolution of our successful FSI solver


20Multi-field Solver – Implementation

Model and mesh

– Single model of physical parts.

– Multiple, separate meshes for each “Field”, derived from base solid model.

What is a FIELD ?

– A FIELD is an Finite Element model set up to perform a single solution

• It may solve for a single physics (e.g. a mechanical structure)

• It may solve for directly coupled physics (e.g.. piezoelectrics)

– A selection of element types is used to define a FIELD

– Each FIELD has it’s own mesh

– Loads, boundary conditions, solver selection are all part of the FIELD definition

– A FIELD may be any analysis type (Static, Harmonic, Transient)

– Each FIELD creates it’s own results file

– A FIELD may be defined (imported) from an external code via a CDB file.



Interfacing between Fields

• Fields “talk” to one another through surface or volumetric interfaces

• Field coupling is realized by mapping loads from one mesh to another

– Support similar or dissimilar meshes

– Supports 1st order and 2nd order elements or mixtures of both

• Automated mesh “morphing” of non-structural domains is available for all non-structural element types.

Multifield Solution

• The solver loops through all fields

• Supports static, transient and harmonic analysis

• Convergence is monitored at the interfaces where loads are transferred.



Time loop: • For transient analysis, refers to solution in time

• For static analysis, refers to each load step

• For harmonic analysis, refers to harmonic analysis within time step

Stagger loop:• Implicit coupling of various fields in time loop

• Number of stagger iterations determined by convergence of load transfer or max stagger iterations

Field loop:• Field solution with specific solution options

• Load transfer to a particular field occurs before solution of the field

• Dissimilar mesh across surface/ volume interface between fields

Time Loop

End Time Loop

Stagger Loop

End Stagger Loop

Field Loop ( i=1,n)

End Field Loop

Physics Field 1

Physics Field 2

Physics Field n


23Multi-field Solver- Physics Loads

PHYSICSPhysics Loads Transferred in Field LoopPhysics Loads Transferred in Field Loop

SEND RECEIVE

CFD Heat flux, Forces, TemperaturesDisplacement, Velocity, Temperature,

Heat rate, Forces

THERMALTemperature, heat flux Temperature, Heat flux, Heat rate,

Displacement

STRUCTURAL Displacement, Velocity Forces, Temperature, Displacement

MAGNETIC Forces, Heat rate Temperature, Displacement

ELECTRIC Forces, Heat rate Temperature, Displacement

High Frequency ELECTROMAGNETIC

Heat Rate Temperature, Displacement


24Multi-field Solver – Multi-user deployment

No need for a super user to handle all physics, separate physics can be processed by individual analysis experts in the company:

Intra-Company ResourceIntra-Company Resource

Multi-field Multi-field AnalysisAnalysis


CAD ModelCAD Model

Physics 1 Engineere.g. CFD

Model pre processing(loads, boundary conditions

& mesh)

Physics 1 Engineere.g. CFD


& mesh)

Physics 2 Engineere.g. ElectromagneticsModel pre processing

(loads, boundary conditions & mesh)

Physics 2 Engineere.g. ElectromagneticsModel pre processing


Physics 3 Engineere.g. Structural


& mesh)

Physics 3 Engineere.g. Structural


& mesh)

Physics 4 Consultant Engineer

e.g. HF electromagneticsModel pre processing


Physics 4 Consultant Engineer

e.g. HF electromagneticsModel pre processing



25

CFD CDB FileCFD CDB FileElectromagnetics

CDB file

ElectromagneticsCDB file Structural CDB fileStructural CDB file HF Emag CDB file HF Emag CDB file

Multi-field Solver – Multi-user deployment

Each physics has its own CDB and results (*.R*) file.

Solid ModelSolid Model

Physics 1e.g. CFD


& mesh)

Physics 1e.g. CFD


& mesh)

Physics 2e.g. ElectromagneticsModel pre processing


Physics 2e.g. ElectromagneticsModel pre processing


Physics 3 e.g. Structural


& mesh)

Physics 3 e.g. Structural


& mesh)

Physics 4 e.g. HF electromagnetics


& mesh)

Physics 4 e.g. HF electromagnetics


& mesh)

Field1.RFL Results FileField1.RFL Results File Field2.RMG Results file

Field2.RMG Results file Field3.RST Results fileField3.RST Results file Field4.RMG Results file Field4.RMG Results file

Multi-field SolverMulti-field SolverMulti-field SolverMulti-field Solver


26Multi-field Solver - dissimilar mesh interface

Example of dissimilar mesh between physics:

CFD mesh: 600,000 elements(Fluid region not shown)

Thermal-mechanical mesh: 15,000 elements


27Multi-field Solver- Summary

• Physics is treated as a "field" with an independent model & mesh

• Each field is defined by a group of element types

• Load transfer regions are identified by surfaces and/or volumes

• Sequential (Load vector) coupling between fields

• Each field may have:

–Different analysis types

–Different solvers and analysis options

–Different mesh descretization

• Each field can be imported from an external solver (e.g. CFX)

• Surface load transfer across fields

• Volumetric load transfer across fields

• Automated morphing of non-structural elements

• Independent results files for each field


28Multi-field Solver- Physics & Applications

Multi-Field Coupled Solver - PhysicsMulti-Field Coupled Solver - Physics Applications/ MarketsApplications/ Markets

Thermal-StructuralThermal-Structural Anything with a structure!Anything with a structure!

Gas turbines. Gas turbines.

Electromagnetic-thermalElectromagnetic-thermal Induction heating, RF heatingInduction heating, RF heating

Electrostatic-Structural - Fluidic:Electrostatic-Structural - Fluidic: MEMSMEMS

Electrostatic – Charged particleElectrostatic – Charged particle Ion Optics, Field Emission Display Technology, Ion Optics, Field Emission Display Technology, Analytical instrumentsAnalytical instruments

Magnetic – Structural - ThermalMagnetic – Structural - Thermal Solenoids, electromagnetic machines, Bus Solenoids, electromagnetic machines, Bus barsbars

Fluid-Solid:Fluid-Solid:

FLOTRAN based FSIFLOTRAN based FSI

CFX-ANSYS unidirectional interfaceCFX-ANSYS unidirectional interface

Aerospace, automotive fuel, hydraulic systems, Aerospace, automotive fuel, hydraulic systems, fluid bearing,fluid bearing,

MEMS fluid damping, drug delivery pumps, MEMS fluid damping, drug delivery pumps, heart valves.heart valves.

Thermal – CFDThermal – CFD Electronics cooling, enginesElectronics cooling, engines

Magnetic - CFDMagnetic - CFD MR fluids, Ferro-fluidics, automotiveMR fluids, Ferro-fluidics, automotive

Third Party/External Product coupling:Third Party/External Product coupling:

Sigfit: Unidirectional, Structural – OpticalSigfit: Unidirectional, Structural – Optical

MpCCI: Bi-directional FSIMpCCI: Bi-directional FSI

Automotive lighting, astronomy, any optical Automotive lighting, astronomy, any optical instrumentsinstruments


29Multi-field Solver- Benefits

• Provides an easy to use framework to solve coupled field problems in ANSYS Multiphysics

• Ability to sequentially couple any number of physics fields

• Applicable across all physics available in ANSYS Multiphysics

• Multiple field specification with different solution option for each field

–Analysis type (Transient/Static/Harmonic)

–Solver options

–Material & geometric non-linearity

• Automated surface and volume load transfer across dissimilar mesh

• Automated Morphing of field elements

• Unidirectional coupling between CFX and ANSYS Multiphysics

• Unidirectional coupling between third party solvers and ANSYS Multiphysics

• Provides analysis opportunities in many new market areas where there have previously been no solutions.


30Multi-field Solver- RF Attenuator Example

RF/microwave energy is attenuated through resistive losses in a Nichrome film attached to the microstripline waveguide. The energy is lost in the form of heat which is conducted both through the devices ceramic substrate and top insulating surface film.

Solid Model:

RF waveguide

Ceramic substrate

Nichrome film

Image from KDI data sheet.

Typical Packaged Device:



HF Emag mesh: 98,175 elements Thermal Mesh: 6,600 elements

Thermal Thermal Physics Field 2

Thermal Thermal Physics Field 2

Heat generation rateHeat generation rate

HF Emag HF Emag Physics Field 1

HF Emag HF Emag Physics Field 1

High-Frequency electromagnetic coupled to a steady-state thermal analysis:



E-field

H-field

Resultant temperature

Analysis results:


33Multi-field Solver- MEMS RF Switch Example

Transient response of MEMS RF Switch to a pulsed voltage excitation:

Beam support post

Ground electrode

Beam electrode

Substrate

Perforation holes to control fluid damping





Physics 1: Mechanical EngineerPhysics 1: Mechanical Engineer

• Mesh solid model of switchMesh solid model of switch• Apply clamped BC’sApply clamped BC’s• Perform squeeze-film damping analysis Perform squeeze-film damping analysis using FLUID136, FLUID138. using FLUID136, FLUID138. • Prepare structural dynamics analysis runPrepare structural dynamics analysis run

Physics 1: Mechanical EngineerPhysics 1: Mechanical Engineer

• Mesh solid model of switchMesh solid model of switch• Apply clamped BC’sApply clamped BC’s• Perform squeeze-film damping analysis Perform squeeze-film damping analysis using FLUID136, FLUID138. using FLUID136, FLUID138. • Prepare structural dynamics analysis runPrepare structural dynamics analysis run

Physics 2: Electronics EngineerPhysics 2: Electronics Engineer

• Create Air mesh around switchCreate Air mesh around switch• Apply voltage BC’sApply voltage BC’s• Prepare electrostatics analysis run Prepare electrostatics analysis run • Write CDB fileWrite CDB file

Physics 2: Electronics EngineerPhysics 2: Electronics Engineer

• Create Air mesh around switchCreate Air mesh around switch• Apply voltage BC’sApply voltage BC’s• Prepare electrostatics analysis run Prepare electrostatics analysis run • Write CDB fileWrite CDB file

CAD ModelCAD ModelCAD ModelCAD Model

MFIMPORTMFIMPORTMFIMPORTMFIMPORT

Each physics model is prepared independently:



Electrostatics Physics Field 2Electrostatics Physics Field 2

Displacement, ForcesDisplacement, Forces

Mechanical Physics Field 1

Mechanical Physics Field 1

Structural mesh: 1894 elements Electrostic mesh: 16,353 elements

Transient, dynamic electrostatics coupled to mechanical analysis:



Displacement of switch mid-planeUnder pulse voltage excitation

Analysis Results:


37Multi-field Solver Example: CFX Imported field

Gas turbine with internal cooling example:

• Unidirectional coupling between CFX and ANSYS

• CFX performs conjugate heat transfer fluid solution.

• CFX writes an ANSYS CDB file containing surface forces, volumetric temperatures; defining an “external field” for the multifield solver

• ANSYS interpolates CFX results onto the ANSYS FE mesh

• ANSYS solves the thermal-stress analysis

• Makes use of Cyclic symmetry (113 blades!)


38

ANSYS Internal Physics FieldANSYS Internal Physics FieldANSYS Internal Physics FieldANSYS Internal Physics FieldExternalExternal Physics FieldPhysics Field

ExternalExternal Physics FieldPhysics Field

Multi-field Solver Example: CFX Imported field

StructuralStructuralPhysics Field 2

StructuralStructuralPhysics Field 2

VolumetricTemperatures

VolumetricTemperatures

InterpolatedVolumetric Temperature

InterpolatedVolumetric Temperature

SurfaceForcesSurfaceForces

InterpolatedSurface Forces

InterpolatedSurface Forces

Details of field stagger loop:

CFX ModelCFX ModelPhysics Field 1

CFX ModelCFX ModelPhysics Field 1



Imported field process:

• Create CFD model in CFX-build,

• Pre-process and Solve Conjugate HT problem in CFX-solve.

• Use the export utility in CFX-Post create a ANSYS CDB file

• CDB file has SUR152/154 elements with force loads and SOLID70 with temperatures

derived from CFX mesh.

• Create solid region in ANSYS Multiphysics and mesh for thermal-stress analysis

• Apply boundary conditions (Omega loading, cyclic symmetry)

• Read in the cdb file from CFX via the MFIMport command

• Create the fluid solid (FSIN) interfaces via SF command for the surface Forces

• Create the solid-solid volumetric (FVIN) interface via BFE command for the temperatures

• User defines solid region as "field2" and fluid (CFX) region as "field1"

• ANSYS 8.0 multi-field stagger loop algorithm is used to transfer loads from "field2“ mesh to "field1 mesh and then solves the thermal-stress analysis."



Field 1: CFD Results

Pressure

Streamlines

Temperature



Field 2: Thermal Mechanical Results

Displacement

Equivalent stress (SEQV)

Temperature


42

• CFX can export the following to ANSYS Multiphysics

– At surfaces

• Nodal heat flux

• Nodal forces

– Within Solid volumes

• Nodal temperatures

• CFX loads can be read only with the ANSYS Multiphysics Multi-field Solver

• CFX5 export

– Stand-alone CFXExport executable available for CFX5.6 customers

– ANSYS CDB file created from CFX results files

– Works with ANSYS Multiphysics 8.0 and the Multifield solver

Multi-field Solver: CFX support


43Topics Covered












• Enhanced non-linear Piezoelectric & piezoresistive elements.

• Direct coupled piezoresistive elements





















• Enhanced non-linear Piezoelectric & piezoresistive elements.

• Direct coupled piezoresistive elements











44

Series 22X elements bring consistency and ease of use to our direct coupled physics:

• Capabilities

– New material models and coupled-field effects

– More special features and loads

• Consistency

– Flexible setting of DOFs and reactions - controlled by KEYOPT(1)

– Element shapes and orders - match our 18X solid structural elements

– Load labels - CHRG vs AMPS

– Large deflection capability - available for ALL analyses with structural DOFs

• New code architecture

– Use existing / enhanced ‘core’ legacy elements as building blocks

– Inherit the functionality of ‘core’ elements - material models, loads, special features.

– Calculate directly coupled-field effects inside the element.

– Facilitates infrastructure to rapidly deploy additional directly coupled physics.

Direct Coupled-Field Elements - Benefits


45Series 22X Coupled Field Elements

• Higher order solid elements for

– Piezoelectric analysis

– Piezoresistive analysis

• Applications

– Pressure transducers

– Sensors

– Accelerometers

– Microphones

• Elements

– PLANE223 2-D 8-Node Quad

– SOLID226 3-D 20-Node Brick

– SOLID227 3-D 10-Node Tetrahedral

• Couples to CIRCU124

– Can build Wheatstone bridge etcImages courtesy Endevco & Fujikura.

Acceleration

R1

R2

R4

R3

Force


46Coupled Field Piezoresistive Element

Strain gauge accelerometer principle of operation:

Proof mass

R1 R2 R3 R4

R1

R2

R3

R4

AccelerationForce

R1

R2

R4

R3

Acceleration

Force

Piezoresistors

R1

R1

R1

normal

compression

tension

piezo-resistor color key

Support Frame



Four Piezoresistor elements

Beam

Strain gauge accelerometer analysis example:• Accelerometer uses four piezoresistive sensors per beam in a Wheatstone Bridge

configuration.• Objective is to compute Output voltage and sensitivity with 5 V DC excitation.• SOLID95 for mass, frame, and beam• SOLID226 for Piezoresistors• Voltage coupling used to create Wheatstone bridge.

Frame

Proof Mass

Detail of beam:



Analysis results for 1 G acceleration load:• Stress in beam: 1.6-2.9 MPa• Differential voltage in bridge: 2.79 mV• Sensitivity: 2.84e-4 Vsec2/m

Axial stress contour plots:


49Damping Elements for Thin Film Applications

FLUID 136 - 2D 4 or 8 node squeeze film fluid element

FLUID 138 - 3D 2 node viscous fluid link element

FLUID 139 - 2 or more node slide film damper

• Applicable to MEMS or macro devices where damping attributed to thin films/ air gaps is required.

• “KEYOPTS” control the flow regime: Continuum, High Knudsen numbers etc.

• The fluid environment is defined by a set of real constants.

• For FLUID136 & FLUID138: The elements are added to the structure and a static analysis is used to determine the damping effects at low frequencies, and a harmonic analysis is used to determine the stiffening and damping effects at high frequencies.

• The DMPEXT command is used to extract frequency dependent damping parameters for use with the MDAMP, DMPRAT, ALPHAD, and BETAD commands for use in structural dynamics analysis with correct damping.

• Accurately extract ALPHA and BETA Rayleigh damping terms for a transient analysis.



FLUID 136:

• Models viscous fluid flow behavior in small gaps between fixed surfaces and structures moving perpendicular to the fixed surfaces.

• Used to determine the stiffening and damping effects that the fluid exerts on the moving structure.

• Based on the Reynolds squeeze film theory and the theory of rarefied gases.

• A static analysis is used to determine the damping effects at low frequencies. A harmonic analysis is used to determine the stiffening and damping effects at high frequencies.

• The DMPEXT command is used to extract frequency dependent damping parameters for use with the MDAMP, DMPRAT, ALPHAD, and BETAD commands for use in structural dynamics analysis with correct damping.

• Accurately extract ALPHA and BETA Rayleigh damping terms for a transient analysis.



FLUID 138:

• Models the viscous fluid flow behavior through short channels (i.e., holes) in microstructures moving perpendicular to fixed surfaces.

• Can be used in conjunction with FLUID136 elements to determine the stiffening and damping effects that the fluid exerts on the moving perforated microstructure.

• Assumes isothermal flow at low Reynolds numbers.

• Accounts for gas rarefaction effects and fringe effects due to the short channel length.

• Can be used to model either continuous or high Knudsen number flow regimes.

• Applicable to static, harmonic, and transient analyses.

FLUID 139:

• 139 is a combination of Couette (low frequency) and Stokes flow (inertial effects at high frequency).

• The viscous flow between surfaces is represented by a series connection of mass-damper elements whereby each node corresponds to a local fluid layer

• Applicable to large deflection.



Damping dominant @ low frequencies represents

fluid displacement effects

Damping dominant @ low frequencies represents

fluid displacement effects

Squeeze or Spring dominant @ higher frequencies

represents compressible fluid effects

Squeeze or Spring dominant @ higher frequencies

represents compressible fluid effects

Squeeze & damping constants:


53

Automated using the DMPEXT command macro

Damping Elements for Thin Film Applications

Computing damping parameters for flexible bodies using the Modal Projection Technique:

• Build a structural and thin-film fluid model and mesh.

• Perform a modal analysis on the structure.

• Extract the desired mode eigenvectors.

• Select the desired modes for damping parameter calculations.

• Perform a harmonic analysis on the thin-film elements.

• Compute the modal squeeze stiffness and damping parameters.

• Compute modal damping ratio and squeeze stiffness coefficient.

• Display the results: MDPLOT.



Transient dynamic response of damped MEMS RF Switch:

Viscous

FEA Model of damping holes:


55Damping Elements – Application Example

Results: Transient dynamic response of the switch to a pulsed voltage excitation. ALPHA and BETA damping parameters were obtained from a squeeze-film analysis of the structure


56

MEMS Accelerometer harmonic response:

Damping Elements – Application Example

Pressure distribution at 20 Hz for design with no damping control holes in the plate.

Pressure distribution at 100 Hz for design with matrix of damping control holes in the plate.


57

MEMS Accelerometer harmonic frequency response 0.1 – 10 kHzShows results of four design iterations:

Damping Elements - Application Examples

Initial design (no plate holes) is overdamped

Final design (honeycomb plate) has

flattest frequency response


58LF Electromagnetic Cyclic Symmetry

Feature:• Cyclic symmetry (periodicity) for Low Frequency Electromagnetics

• Commands: CYCLIC and CYCOPT

• Supports: PLANE13, PLANE53, SOLID96, SOLID5, SOLID98, SOLID117

Benefits:• This new feature is applicable to 3D magnetic scalar potential (MSP),

magnetic vector potential (MVP) and edge (SOLID117) formulations .

• These commands are also used for cyclic symmetry structural analyses results greater consistency across physics.

• Reduce FEA problem size & faster solution time by making use of symmetry.

Market applications:Primarily rotating electromagnetic machines

• Electric motors

• Alternators

• Inductive ignition system sensors



Example: 4 pole variable reluctance machine reduced to 90 degree sector:

Bcircumferential




61Low Frequency Electromagnetic Contact

Feature:• Contact for Low Frequency Electromagnetic

• Commands: TARGET169, CONTAC171

• Supports: PLANE13, PLANE53, SOLID96, SOLID5, SOLID98

Benefits:• This new feature is applicable to 3D magnetic scalar potential (MSP), and

2D magnetic vector potential (MVP).

• A lot easier to use than constraint equations!

Market applications:• Electric motors

• Alternators

• Inductive ignition system sensors

• Linear Motion Systems

• Non Destructive Testing

• Eddy current braking systems


62Low Frequency Electromagnetic Contact

Example: “In pipe” eddy current based sensor. Sensor slides down pipe detecting flaw in pipe wall.

B-field contours

Pipe

Sensor


63Ion Optics Enhancements

Ion Optics - An important feature for the SEMICON and Analytical instrument markets:

• Particle tracing is a post processing feature.

• Can trace charged particle in either a electrostatic field or magnetostatic field or both.

• Particles initial conditions definable are:– Mass

– Charge

– Starting coordinates (x,y,z)

– Velocity vector (Vx,Vy,Vz)

• Can define 50 particles per run.

• Particle trajectory can be plotted in 2D/3D or listed.

• Space charge effects are not accommodated.

• No relativistic effects (velocity is much smaller than speed of light).



Example of a particle trace through homogenous magnetic field, with a changing electric field. Animation is a composite of static cases



Example of a particle trace on a charged particle trace! PLTRACE command used to slide “visualization particles” along the charged particle trajectories.


66FSI – Remeshing Enhancements

Coupled fluid-solid (FSI) meshing capability enhanced to handle applications with large boundary/domain changes.

This feature opens up a broader range of FSI market applications:

• Solid can undergo large deformation or complete rotations. E.g.. Pumps or stirrers.

• Detached solid object movement through fluid.

Enhancements:

• Moving boundary problem is re-meshed when mesh becomes badly distorted or ALE mesh morphing scheme fails.

• Improved accuracy when the mesh is distorted by ALE mesh moving scheme

• Regenerates a new mesh from a selected element group.

– All element based loads (e.g. FSI interface) are updated

– Body loads on the interior nodes are updated

• Nodal values are interpolate from old mesh to new mesh

• Redesigned FLOTRAN result files, creates new rfl file for each remesh

• Animation is possible across multiple result files (anmres)



New Commands:• FLDATA39, REMESH, Label, Value

• ANMRES, Delay, Min, Max, Inc, Autocntrky, Freq, ’rfl’

Limitations:

• Must keep the same topology for surface (boundary) elements.

• Applicable to triangle (2D) and tetrahedral (3D) elements

Example: Rigid body rotation, a flap valve in a tube:



Cylinder passing through a channel:


69Topics Covered












































70Selected Multiphysics

• Thermal-structural coupling

• Needed for any product subjected to changes in temperature!– Engines, gas turbines, heat exchangers

– Electronic components, package solder joints

– Cryogenic components and systems

– Test & Measurement Equipment

HeatHeatTransferTransfer


SolidSolidMechanicsMechanics



71Thermal Structural Example

BGA IC Package differential thermal expansion

Image courtesy of MCR.



• Thermal-Fluid Coupling (Conjugate heat transfer)– Heat is transferred between fluid and solid

– Convection effects.

– Forced flow.

• Applications:– Heat exchangers

– Electronics device/enclosure temperature management



FluidFluidMechanicsMechanics



73Conjugate Heat Transfer Example

Vertical heat sink



• Electro- Thermal Coupling– Resistive (Joule) heating

• Electro-Thermal-Structural coupling– Resistive (Joule) heating resulting in thermal expansion

• Needed for many electronic power handling components and systems. – Current-carrying conductors, bus bars

– Electric motors, generators, transformers

– Electronic components and systems

– Actuators



Solid Solid MechanicsMechanics

Solid Solid MechanicsMechanicsElectricityElectricityElectricityElectricity


75Electro-Thermal-Structural Example

Current Density Electrical Power Thermal Stress

Images courtesy of Atila Mertol, LSI Logic.

Detail of Integrated Circuit via & aluminum trace



• Electrostatic – Structural coupling

– Piezoelectric effect

• Electrostatic-structural-Fluid Coupling

– Electrostatic actuated structures incorporating effects of fluid damping.

• The entire MEMS Industry is based on these physics!

– Resonators/Actuators

– Electro-mechanical band pass filters

– Inertial sensors (Accelerometers & gyroscopes)

– Inkjet printer heads



Fluid Fluid MechanicsMechanics

Fluid Fluid MechanicsMechanicsElectrostaticElectrostaticElectrostaticElectrostatic


77MEMS Micromirror Example



• Electromagnetic-Thermal coupling– Eddy current losses (LF Emag)

– Resistive & dielectric losses (HF Emag)

• Applications:– Required by those that want heat or those that want to minimize it!

– Induction heating systems (LF Emag) • Heat treating processes

• Pre-heating for metal forming operations

– RF Microwave systems (HF Emag)• Heaters

• Attenuators



Electro-Electro-magneticsmagnetics



79Induction Heating Example

– Solid model meshed

– Current in coil

– Induced current in plate

– Resultant B-Field


80Induction Heating Example

– Joule heating

– Time averaged joule heating thermal load

– Resultant temperature



• Electromagnetic - Fluid coupling

• Applications– Magneto-Rheological (MR) devices

• Active structure vibration damping systems

• Automotive & biomedical actuators

– Induction furnaces for stirring molten metals

– MHD power systems, EHD pumps






82Electromagnetic - Fluid coupling Example

A.C. Induction furnace:

• Electromagnetic field solution to compute Lorentz forces

• CFD analysis performed to determine stirring pattern within furnace core



• Electromagnetic – Solid Coupling– Forces due to magnetic field move/interact with mechanical

structures.

– Magnetic force (linear systems)

– Magnetic torque (rotary systems)

• Applications:– Actuators / Solenoids

– Rotating machines• Alternators

• Motors






84

Moving Magnetic Probe Example

2D Axi-symmetric model using true moving object, sliding mesh boundary Animation of flux lines when V = 0.4 m/s


85

Magnetic Levitation Example

Flux lines and levitation coil currents:


86

Rotating Machine Examples

Images courtesy of CAD-FEM GmbH.



• Thermal-Solid-Electromagnetic Coupling– Thermal-mechanical dimensional changes coupled into HF

Emag or LF Emag analysis.

• Many applications require knowledge of the effects of temperature on electromagnetic performance.




Solid Solid MechanicsMechanics ElectromagneticsElectromagneticsElectromagneticsElectromagnetics


88

Waveguide BendWaveguide BendElectric FieldElectric Field

@ 20@ 20ooCC

WaveguideWaveguideDisplacementDisplacementfrom 20- 60from 20- 60ooCC

Waveguide BendWaveguide BendElectric FieldElectric Field

@ 60@ 60ooCC

20 20 ooC : SC : S1111 = 0.1901, S = 0.1901, S1212 = 0.9817 = 0.9817

60 60 ooC : SC : S1111 = 0.1895, S = 0.1895, S1212 = 0.9819 = 0.9819

Thermal-Solid-Electromagnetic Coupling Example

Thermal Effects on microwave wave guide





Viscous Fluid Viscous Fluid MechanicsMechanics

Viscous Fluid Viscous Fluid MechanicsMechanics

• Coupled Fluid – Solid (Fluid Solid Interaction, FSI)– Fluid pressure deforms mechanical structure which in turn

effects fluid flow. May also include heat transfer.

• Applications– Aero-elastic problems

– Hydraulic / Pneumatic / Fuel systems

– Fluid pumps

– Biomedical

• Blood flow – elastic artery

• Heart valves


90FSI Example – Pressure Limiting Valve

0.25 mm

Ø 2.4 mm

Ø 4.0 mm

Ø 4.5 mm

Ø 10.0 mm

55º

• Pressure-limiting valves are used in anti-lock brake systems

– Huge liability ramifications

• Per VDO, tiny geometric design changes cause wide variations in valve response and performance

• Without FSI VDO was guessing on new valve designs.

• FSI analysis significantly reduces overall time to market and improve reliability.

Courtesy : Siemens VDO


91FSI Example – Pressure Limiting Valve

Mesh detail & dissimilar mesh for solid & fluid



92FSI Example – Results



93FSI Example – Results


Ball displacement time history, f 875 Hz



• Inviscid fluid-structural coupling (FSI)– Longitudinal pressure wave travels through fluid causing

displacement of solid structure.

• Applications (Primarily acoustics):– Loudspeaker design

– Microphone

– Sonar / ultrasonics

Inviscid FluidInviscid FluidMechanicsMechanics

Inviscid FluidInviscid FluidMechanicsMechanics




95Acoustics Example

Response of axisymmetric disc in tube to plane wave.


96Topics Covered












































97Product Roadmap - Overview

• Target markets:• Actuator and Sensors

• Low Frequency (Actuators and electric machines)

• MEMS

• High Frequency (RF) devices

• Biomedical - FSI

• Short/Medium Term (< 2 years):

– Release 8.1/9.0

• ROM140 (Damping counterpart to ROM144)

• Publish ROM database format & provide additional ports on ROM144 for drive variable

• LinkCAD for ANSYS Process Emulator module

• CFX ANSYS integration

• Longer Term (2 - 3 years):

– Products and technology migrated to ANSYS Workbench Environment.

– CFX will take FLOTRAN’s place in the ANSYS Workbench Environment.

– MEMS coupled analysis capability in Workbench Environment.


98Roadmap – Transition to Workbench

• Objective is to migrate ALL physics technology to Workbench

• We will not to develop standalone physics products….Products and physics will instead be more modular and controlled through licensing.

• Strategy is to migrate and expose technology into the ANSYS Workbench Environment creating a general purpose product applicable to a broad range of markets.

• Order of physics exposure is:

– LF Emag

– CFD (CFX technology)

– HF Emag

– Advanced Physics


99Topics Covered












































100Product Websites


101Product Websites – FSI & MEMS


102The End!

Acknowledgements:

– Dale Ostergaard– Barry Christenson– Deepak Ganjoo– Ray Browell– Bill Bulat– Achuth Rao– Stephen Scampoli– Daniel Shaw– Mark Troscinski– Miklos Gyimesi– CAD-FEM GmbH

Date post:	25-Jan-2016
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ANSYS Multiphysics 8.0 Technology Overview & Benefits

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