Ic Engine Ansys

7/22/2019 Ic Engine Ansys

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ICEngine

System

PresentedBy

ANSYSInc.


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BackgroundandMotivation

ICEngineSystem

Introduction

Scope

Properties

Workflow

for

cold

flow

and

port

flow

simulations

Advancedsetup/customization

Otherusefulfeatures

Demo FuturePlans

Summary

Outline


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In-Cylinder

Cooling Jacket Lubrication

Intake

Exhaust

Pumps

Turbocharging

AmonginternalcombustionengineCFDapplications,

incylinderflowisofcentralimportanceindetermining

engineefficiencyandemissions

Fuel Supply


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RecentANSYS

Progress

in

IC

Engine

Modeling

20102009

ContinuousprogresswitheachFluentreleasebringing

advancementsinphysicsandmeshing

FluentR12ICenginereport,ICspecific

vaporizationlaws,coherent

flamelet model,EGR,

ignitionUDF

FluentR13Keyframemesh,meshsmoothing,

DPMandcombustionextensions:

multiplesparkmodel,Veynante ECFM

forLES,KHRTbreakupmodel,

FluentR14.5Sprays:sprayanglevs.crankangle,

coneinjectionsectormeshes

Meshrelated:2nd orderintimeMDM,

contactdetection,cutcell w.BLremesh

2011 2012

FluentR14Aftertreatment:selective

catalyticreduction,catalytic

converterlightoff

Combustion:G

eqn

Multiphase:SSD

*TheWorkbenchICEnginesystemusesawelltestedsubsetofFluentfeatures


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ManualApproachforsimulatingincylinderflow

Gathertherequireduserinputneededtoaccuratelymodeltheusersspecificengine.

PreparetheGeometryandMesh:

Decomposethegeometryinamannersuitableformodelingthemotionofvalvesandpistonandthencreatethemesh

Manuallydecomposingthegeometryandmeshingtakes

between6hours

and

acouple

of

days,

depending

on

experience

Learningcurveformanualgeometrydecompositionandmeshingisverysteep!!

Setup andrunthesimulation:

Settingupthecaserequiresknowledgeofmodelslikedynamicmesh,reactingflows,discretephaseetc.

Analyze

and

interpret

results

Motivation

ICEngine

Geometry

Geometry

Decomposition

MeshCreation

SolverSetup

ICEngine

Results

WBICEtoolPerformfollowingoperationssemi

automatically

Geometry

DecompositionSolverSetup

MeshCreation

Automatic

Report

Generation


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ICEngineSystem

AnewWorkbenchAnalysisSystem

similartoFluidFlow(Fluent)orFluidFlow(CFX)AnalysisSystems

ReducesthesetuptimeofICEcold

flowand

port

flow

problems

from

manyhourstofewminutes

FirstreleasedANSYSR14

Supported

on

Windows

and

Linux

platforms

Standard featureincludedwith

ANSYSFLUENT

IC

Engine

System:

Introduction


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Automatedgeometrypreparationandmeshgeneration

forall4strokeengines

any

number

of

valves

allstandardshapesofpistonatthegivencrankangle

Automatedcasesetupforcoldflowandportflow

typesimulations

based

on

the

best

practices

includingmeshmotion

Userhooksforcomplexphysicssetup,e.g.sprayinjection,

combustion

simulation Automatedreportgeneration

Scope

of

IC

Engine

System


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IC

Engine

System

Properties

TheseICinputs

canbedefinedas

Parameters

Canbe

used

to

setupa

customizedcase

Canbeusedto

perform

custom

postprocessing

Forengines

withpiston

pinoffset

Usercanhook

boundary

condition

profiles


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ANSYSWorkbench

WorkbenchICESystem

DesignModeler

FLUENTSolver

CFDPost

Single

Mesh

ANSYSMeshing

Multiple

Meshes

(keyframes)

(newR14.5)

Automatically

GeneratedReportsCAD


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ColdFlowSimulationSetup

UsingIC

Engine

System:


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Automaticpreparationofgeometryformeshing

Automatic

meshing

including

inflation

layers

and

layeringzones

Automaticsetupdynamiczones,events,andsolver

settings HTMLreportcreation

Reducestheturnaroundtime(CADimporttoCFD

setup)to

less

than

an

hour

Cold

Flow

Simulation

using

IC

Engine

System


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Geometry

Preparation


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Geometry

Inputs

BasicGeometry

Information

Valvegeometry

and

profileinformation

Optional

AnimationInputs

Advanced

Options


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Mesh

Generation


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Different

Meshing

Configurations

4layersbetweenvalve

andvalve

seat

at

fully

closedpositionofvalve

onelayerinthegapat

fully

closed

position

of

valve


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Inflation

layer

in

the

port

NoInflationlayerintheport

Different

Meshing

Configurations


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DifferentMeshing Configurations

Nodecompositionin

chamber

region

for

engineswithverylittle

squishatTDCorpistons

withvalverecessregions

Decompositionin

combustionchamber

regionforlayeredmesh


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ICEngineSystemwillautomaticallysetupthe

problem

Reads

the

valve

and

piston

profile

Createvariousdynamicmeshzones

Createinterfacesrequiredfordynamicmeshsetup

Setupthedynamicmeshparameters

Create

all

the

required

events,

to

model

opening

and

closing

of

valves,andcorrespondingmodificationsinsolversettingsand

underrelaxationsfactors

Setuptherequiredmodels

Set

up

the

default

boundary

conditions

and

material

Setupthedefaultmonitors

Initializeandpatchthesolution

SolverSetup


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Once the solution is complete, tool creates adetailed report with all the settings , events,

results and images.

HTMLReport


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PortFlowSimulationusing

ICEngine

System


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NewfeatureinupcomingANSYSR14.5Release

Preparesthegeometryautomatically

Automaticmeshingusinghybridandcutcell

approaches

Setupand

solution

strategy

based

on

the

best

practices

AutomaticsavingofimportantimagesandHTML

reportcreation

Reducestheturnaroundtime(CADimporttoCFD

setup)tolessthananhour

PortFlowSimulationusing

ICEngineSystem


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AutomaticGeometry

Preparation

Movesthevalvetoappropriateposition

Deactivatestheclosedvalveanddeletestheport

automatically

Removesthepistonbowl(ifneeded)andextendthe

cylindertoappropriatelength

Createdifferentshapesofinlet/outletplenum

Automaticallycreatestheswirl/tumbleplanesatthe

givenposition


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OriginalGeometry Input

Manager

for

PortFlow

Finalgeometrywith

InletandOutletPlenums,

andport

deactivated

AutomaticGeometryPreparation


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GeometryDecomposition


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Cutcell andhybridmeshingsupport

Createpropermeshcontrolsandsizingto

getbettermeshinthechamberandvalve

gap

Boundarylayersinbothhybridandcutcell

meshing

AutomaticMeshing


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AutomaticMeshing


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ICEngineSystemwillsetupthesolverfromthebest

practicesforcutcell andHybridmeshing

Setappropriatesolvermethodsandcontrols

Settheboundaryconditions

Definesthedefaultmonitors

Does

the

FMG

initialization

Automaticallycreatesthedefaultswirlplanefrom

geometryinformation, anddefinescustomfield

functionsfor

swirl

AutomaticSolverSetup


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HTMLReport:


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Demo(56minrecorded

demoof

cold

flow

and

port

flow)


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Astrongregressionsuite

Morethan15engineswithvarioustopologies

fromdifferentcustomersare thereinourregressionsuite,whichrunsondailybasis,to

maintainthestability andhighqualityof

software

Foreachoftheseenginesgeometrypreparation,

meshing,andsetupforcoldflowcaseiswithin20

min,and

for

port

flow

this

is

within

30

min

RegressionandTimeStatistics:


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Documentation: Detailedexplanationofallthefeatureswithtipsonhowonecan

modifythedefaultbehaviorofthetool

Troubleshootingchapters:Alltheknowledge gainedsincetherelease

of

14

has

been

captured

and

documented.

Separate

sectionsfor: Geometrycheck

Geometrypreparation

Meshgeneration

Solversettingup

Welldocumentedprocessexplaininghowtoolcanbeextendedforsomeofthefeatureswhicharenotsupportedbyautomation

Decomposingastraight

valve

engine

with

pockets

for

layered

meshing

Handling geometriesinwhichsolidvalvesaremissing

DetailstepsforsettingupandrunningthetutorialsalongwithVidetutorials


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Extendingthe

Tool

(Advanced

Users)


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Userwillbeabletosetupadvancedphysicsusingpre

iterationandpostiterationjournalhooks

Usingpre

iteration

journal

hooks

user

should

be

able

to

setupcombustionprobleminICEnginesystem:

Defineprofile,udf , andchemkin,filepathandalsoother

variables

Compileandhooktheudf,alsodefinesomeudf related

variables

Deactivateportfluidzones

Set

up

energy

model,

turbulence

model,

species

model

and

dpm models

Defineinjections

Advancedsolversetupusing

journalcustomization.


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SettingupCombustion:

Preiteration

Journal

ColdFlow

Setup

Combustion

Setupwith

Spray


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PreiterationJournalfile

forcombustion:

FileHandling

ModelControl

InjectionData

SetupMethod


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YoucancreatenewZoneat

geometrylevel

by

defining

aNamedSelection with

prefixiceuser

Extendtheboundary

conditionsby

defining

new

boundaryconditionsin

UserBoundaryConditions

and

Monitor

Settings

Creatingnewzonesanddefining

advancedboundary

conditions.


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HandlingEngineswith

CreviceRegion

CreviceRegion

Interface

HexMesh

Though,rightnow,thetoolwillnot doanyspecial

treatmentforcreviceregion,onecanextendthe

toolbydoingfewmanualoperationstogetmore

controlin

crevice

region

Separatethecrevicevolume anddefine

propermesh

Defineinterfacestohandlethisnewcrevice

volume


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OtherUsefulFeatures


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Keygridsupport

Automaticcrankanglespecificdecomposition

Createmeshasperthecrankangleposition

Parametricsupporttogetmeshesatdifferent

crankangles

Youcansetupuptothemeshonce,andthen youcan

createany

number

of

design

points

with

the

exposed

parameterslike:crankangles,minimumlift,or

connectingrodlengthandupdatethedesignpoints,

you

will

have

the

appropriate

mesh

file

ready

at

those

givencrankangleswithoutanymanualintervention


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Keygridsbasedonthecrankangle

Geometry

andMeshat

crankangle

near TDC

Geometry

andMesh

at

crankangle

near BDC


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UsabilityFeatures

Animationofvalveandpistonmotionforthecoldflow

simulationatgeometrylevel

Parametersupport

for

port

flow

solution

and

mesh

generationincoldflow

Usercanstartthecoldflowsimulationfromanycrank

angle,all

the

settings

will

be

taken

care

automatically

Thissavesahugeamountoftime;earlierpeopleuse

toreachtherequiredcrankanglebymeshmotion

which

takes

a

lot

of

time AutomaticcutplanesandviewsinAMPfor better

visualizationofthemesh


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SmoothtransitionfromColdflowtoSprayandCombustion

Automatedsetupforcombustionanalysis

Improvemeshing

options

by

AutomaticallySwitchingbetweendifferenttailored

meshesduringsimulation(Keygridormesh

replacement

approach)

FuturePlans

Note:Theplansarestilltentativeandtimelines,prioritiesetc.needstobeworkedout


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NewstandardfeatureinANSYSFLUENTforIn

Cylindersimulations

Automatesin

cylinder

model

creation

Extensivelytestedondifferentengine

configurations

SupportedonWindowsandLinux

Quicktolearnandeasytouse!

Provideshooks

for

custom

in

cylinder

simulations

Summary


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Appendix


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WorkFlow


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Meshconfigurationof

ICEngine

system

for

atypical

canted

valve

engine

No FluidZone

Name

Mesh type

1 fluidch Tet mesh

2 fluidvalveID

ib

Sweep meshwithat

leastonelayeratthe

top

3 fluidvalveID

port

Tet meshwith or

withoutprismlayer

4 fluidvalveID

vlayer

Layered meshwith1

or4layers

5 fluidlayer

cylinder

Layeredmesh

6 Fluidpiston Tet mesh


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Various zonesandnamedselectioncreatedautomaticallyforatypicalcantedvalveengine.

Geometrydecomposition


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SmoothingLayeringapproach

smoothing smoothinglayering

Toretainatleast4

layersofcellsbetween

valveandvalveseat,

throughoutcycle


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PistonshouldbeatTDCposition(inR14.0)

ForParasolid geometry,settheCleanBodiesoptiontoNo

Importedgeometry

should

haveonlyoneflowvolumewithsolidvalves

Ensurethatthevalvesarenotextractedfromtheport

volumein

the

initial

geometry

Ensurethatthevalvestemprotrudesoutoftheportbody

Ensurethatthevalveiscentrallyalignedtothevalve

guide.

An

off

centered

valve

canresult

into

failures

and

wrongresults

Troubleshooting:GeometryCheck


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Ifcylinderchambermeshingfails=>Deleteitspinchcontrolsandexecutethe

meshingagain

Ifsome

faces

belonging

to

anamed

selectiongrouparenotselectedfortheGeometryoptiontheybelongto,thenthewarningisdisplayed=>AddthesefacestotheGeometrylistof

theNamedSelectionitbelongsto

Ifthereareanysmallfacescausinga

meshingfailure,

then

these

faces

shouldbemergedwiththeiradjacentfacesusingVirtualTopology

IfVlayermeshingfails=>Trytoprojectandimprinttheedgeofthe

valvefaceonthevalveseat,inthe

direction

of

the

valve Thiswillsplitthevalveseat.Then

decomposethegeometryagain.Thisprocedurewillcreateapropersweepmeshinthevlayer.

Troubleshooting:Mesh

Generation


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Vlayermeshingcanfailinsomecaseswherethefacehasastep.

SelectShow

the

ProblematicGeometryfromthecontextmenuoftheerrormessageintheMessageswindow.Thiswillpointtothefacewhichhas

thestep

ReducetheVLayerSliceAngleparameterintheInputManager,suchthatthefaceissplitintotwo.

Then

reset

the

Mesh

cell

andfollow

the

meshing

proceduretoremeshthegeometry.

Troubleshooting:Mesh

Generation


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StraightValveEngineswithValvePockets

Fullylayeredmeshcanbe

createdforstraightvalvediesel

engineswith

valve

pockets

Instructionscanbeprovided

uponrequest(availablein

R14.5ICEManual)

Example:Hexmeshcreatedforlayering

Documents

Ic Engine Ansys