001 Introduction to CFD 29-02-2024 (1).pdf

introduction to CFD

1. COMPUTATIONAL FLUID
DYNAMICS
1
ST
WEEK
University of Engineering and Technology
Lahore, Pakistan
by
Dr. Muhammad Mahmood Aslam Bhutta
Department of Mechanical Engineering
PakistanLahore

2. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Computational fluid Dynamics
Engg. Dr. Muhammad Mahmood Aslam Bhutta
Associate Professor

3. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Introduction
to
Computational Fluid Dynamics

4. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Resource Person
HereceivedB.Sc.&M.Sc.MechanicalEngineeringdegreesfromUniversity
ofEngineeringandTechnology,Lahore,Pakistan.HehasearnedDoctorate
degreeinMechanicalEngineeringfromtheTechnicalUniversityGraz,Graz,
Austria.
ThefocusofhisPhDresearchwasCFD(ComputationalFluidDynamics)
SimulationofHighSpeedTwoStrokeEngine.Hehaspublicationsin
nationalandinternationaljournalsincludingimpactfactorjournals,having
1500pluscitations.HehassupervisednumerousMSandPhDtheses.
Hehasoverallindustrial,teachingandresearchexperienceof35years.His
currentresearchinterestsincludeEnergy,ICEnginesandapplicationof
CFD.
Dr. Muhammad Mahmood Aslam Bhutta
Professor,
Department of Mechanical Engineering,
UET, Lahore.

5. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Introduction
■ComputationalFluidDynamicsorCFDistheanalysisof
systemsinvolvingfluidflow,heattransferandassociated
phenomenasuchasbymeansofcomputer.
■AtoolforsolvingPartialDifferentialEquations
■3fundamentalprinciplesoffluidflow:
Massisconserved(ContinuityEquation)
Newton’ssecondlaw(Navier-StokesEquation)
Energyisconserved(Bernoulli’sEquation)
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6. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Introduction
■Governingequations-PDE’sorintegralequations
■beforeCFDforsolvingfluidflowproblemsAnalyticaland
experimentalapproach
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7. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Numerical Solutions (New)
■Computerscanonlydothefollowing:
□Add
(Subtract,MultiplyandDividearedonebyaddition)
□Performsimplelogicaloperations
□Displaycolorsonthescreen
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8. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Introduction
■CFD-Scienceofdetermininganumericalsolutiontothe
governingequationsoffluidflowwhileadvancingthe
solutionthroughspaceortimetoobtainanumerical
descriptionofthecompleteflowfieldofinterest.
■Itisveryimportanttoknowvelocity,pressureand
temperaturefieldsinalargeno.ofapplicationsinvolving
fluidsi.eliquidsandgases.Theperformanceofdevicessuch
asturbomachineryandheatexchangersisdetermined
entirelybythepatternoffluidmotionwithinthem.
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9. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Inthelate70thisapproach(theuseofsupercomputerstosolveaerodynamic
problemsbegantopayoff.OneearlysuccesswastheexperimentalNASA
aircraftcalledHIMAT(HighlyManeuverableAircraftTechnology),designed
totestconceptsofhighmaneuverabilityforthenextgenerationoffighter
planes.
WindtunneltestsofapreliminarydesignforHiMATshowedthatitwould
haveunacceptabledragatspeedsnearthespeedofsound;ifbuiltthatway
theplanewouldbeunabletoprovideanyusefuldata.Thecostofredesigning
itinfurtherwindtunneltestswouldhavebeenaround$150,000andwould
haveunacceptablydelayedtheproject.Instead,thewingwasredesignedbya
computeratacostof$6,000.
PaulE.Ceruzzi,Curator,NationalAirandSpaceMuseum,inBeyondthe
Limits,TheMITPress,1989
History

10. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Computationalfluiddynamics(CFD)isbasicallyusedfor
predictingfluidflow,heattransfer,masstransfer,chemical
reactions,andrelatedphenomenabysolvingthemathematical
equationswhichgoverntheseprocessesusinganumerical
process
•CFD is a simulation tool, which uses a power computer
and applied mathematics to model fluid flow situations.
What is CFD?

11. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Commercial codes for CFD
1.CFX( Ansys)
2.FLUENT(Ansys)
3.STAR-CD
5.FLOW3D
6.CFD-ACE
7.GTPower
8.FLO++
9.CFD++

12. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Computational Fluid Dynamics history
•In1928,theapplicationofCFDstartedinfluidflow
•DaimlerChryslerwasthefirstcompanytouseCFDin
Automotivesector.
•SpeedowasthefirstswimwearcompanytouseCFD
•TheadoptionofCFDtechnologybyfoodengineersbeganin
the1990s.

13. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Why CFD?
■Growthincomplexityofunsolvedengineeringproblems
■Needforquicksolutionsofmoderateaccuracy
■Absenceofanalyticalsolutions
■Theprohibitivecostsinvolvedinperformingevenscaled
laboratoryexperiments
■Efficientsolutionalgorithms
■Developmentsincomputersintermsofspeedandstorage
■Serial/parallel/webcomputing
■Sophisticatedpreandpostprocessingfacilities
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14. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Procedure
1.Virtualmodelisdeveloped(2Dor3D)
2.Theflowregionorcalculationdomainisdividedintoa
largenumberoffinitevolumesorcells(discretization)
3.Solutionmethodisselected
4.Boundaryconditionsareapplied.
5.Solutionprocedureisselected(steadystate,ortransient)
Steadystate(nochangeinconditiononthebasesof
time)
6.Solved
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15. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
■CFDtodayisequalpartnerwithpuretheoryandpure
experimentintheanalysisandsolutionoffluiddynamic
problems.
■Itnicelycomplementspuretheoryandpureexperiment,
butitwillneverreplaceeitheroftheseapproaches.
■with the help of CFD numerical experimentsare carred
out
■TheseNumericalexperimentsgoinparallelwithphysical
experimentsinthelaboratory,thesecanbesometimes
usedtohelpinterpretphysicalexperiment.
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16. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Advantages of CFD
■CFDcomplementsexperimentalandtheoreticalfluiddynamicsby
providinganalternativecost-effectivemeansofsimulatingreal
flows.
■Insight
ItgivesBettervisualizationhenceenhanceunderstandingofflow
designs.
■Foresight
Testingmanyvariationsuntilyouarriveatanoptimalresultbefore
physicalprototypingandtesting.Practicallyunlimitedlevelof
detailofresultswithnoaddedexpense.
■Efficiency
CFDreducesthecostandtimeofdesign&developmentcycle.
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17. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Advantages of CFD
■TheCFDsimulationresultsinpredictionoftheflowfieldsand
engineeringparameters,whichareveryusefulintheDesignand
Optimizationofprocessesandequipment's.
■withCFDthereisaSubstantialreductionofleadtimesandcostsof
newdesigns
■itgivesanAbilitytostudysystemswherecontrolledexperimentsare
difficultorimpossibletoperform(e.g.verylargesystems)
■alsogivesanAbilitytostudysystemsunderhazardousconditionsat
andbeyondtheirnormalperformancelimits(e.g.safetystudiesand
accidentscenarios)
■CFDisslowlybecomingpartandparcelofComputerAided
Engineering(CAE)
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18. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Limitations
•TheCFDsolutionscanonlybeasaccurateasthephysicalmodelson
whichtheyarebased.WithAIitcanbeimproved
•Solvingequationsonacomputerinvariablyintroducesnumericalerrors.
-Round-offerror:duetofinitewordsizeavailableonthecomputer.
Round-offerrorswillalwaysexist(thoughtheycanbesmallinmost
cases).
-Truncationerror:duetoapproximationsinthenumericalmodels.
Truncationerrorswillgotozeroasthegridisrefined.Mesh
refinementisonewaytodealwithtruncationerror.
•Boundaryconditions.
-TheaccuracyoftheCFDsolutiondirectlydependsupon
initial/boundaryconditionsprovidedtothenumericalmodel.

19. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Importance of CFD
■Complements actual engineering testing
■Reduces engineering testing costs
■Provides comprehensive data not easily obtainable from
experimental tests.
■Reduces the product-to-market time and costs
■Helps understand defects, problems and issues in
product/process
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20. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Benefits of CFD
Reduce System Cost
Improve Performance
Understand Problems
Reduce Design Time & Cost

21. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan

22. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Applications of CFD
■Aerodynamics of aircraft : lift and drag
■Automotive : External flow over the body of a vehicle or
internal flow through the engine, combustion, Engine
cooling
■Turbo machinery: Turbines, pumps , compressors etc.
■Flow and heat transfer in thermal power plants and
nuclear power reactors
■HVAC
■Manufacturing -Casting simulation, injection moulding
of plastics
■Marine engineering: loads on off-shore structures
■Hydrodynamics of ships, submarines, torpedo etc.
Biomedical engineering:
Flow in arteries, blood vessels, heart, nasal cavity,
Inhalers

23. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
ApplicationsofCFD
■Electricalandelectronicengineering:
coolingofequipmentlike
transformers,Computers,microcircuits,Semiconductorprocessing,
Opticalfibermanufacturing
■Chemical process engineering:
mixing and separation, chemical reactors, polymer molding
Transportofslurriesinprocessindustries
■Environmentalengineering:
Externalandinternalenvironmentofbuildings,windloading,
Investigatingtheeffectsoffireandsmoke,distributionofpollutants
andeffluentsinairorwater.
■Hydrologyandoceanography:flowsinrivers,oceans
■Meteorology: weatherprediction.
■Geophysicalflows:atmosphericconvectionandgroundwater
movement,Enhancedoilrecoveryfromrockformations

24. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Aerospace)
• Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC&R
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
F18Store Separation
Wing-Body Interaction
Hypersonic Launch Vehicle

25. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Aerospace applications
The moving mesh technology in ANSYS FLUENT software is used to model the changing tilt of the
rotorcraft's wings while changing flight modes.
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26. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Aerospace applications
Contours of pressure on a helicopter in hovering flight mode
20
Vortical structures generated by an aircraft landing gear

27. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Appliances)
• Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC&R
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
Surface-heat-flux plots of the No-Frost
refrigerator and freezer compartments helped
BOSCH-SIEMENS engineers to optimize the
location of air inlets.
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28. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Automotive)
• Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC&R
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
External Aerodynamics
Interior Ventilation
Undercarriage
Aerodynamics
Pressure distribution on a
pickup van

29. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Automotive applications
Automotive in-cylinder flow modeled
Internal combustion engine and the flow inside modeled using
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30. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Surface pressure distribution in an automotive engine cooling jacket.
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31. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
2269.57
215626
2042.95
192964
1816.33
170302
158971
14764
136309
124978
113648
102317
909856
796547
683237
Temperature
distribution
in IC Engine
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32. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used?
• Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC&R
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
Medtronic Blood Pump
(Biomedical)
Spinal Catheter
Temperature and natural
convection currents in the eye
following laser heating.

33. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Biomedical applications
Pathlinesof blood flow in an aneurysm
ANSYS CFXsoftware Is fully integrated in ANSYS
Workbench.Thisbiomedical aneurysm model shows
the stresses in an artery walL
28
•Blood flow
•Medicine mixing
•Heart failure
•Brain Damage (bursting of blood vessels)

34. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Chemical Processing)
Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC&R
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
Polymerization reactor vessel -prediction
of flow separation and residence time
effects.
Twin-screw extruder
modeling
Shear rate distribution in twin-
screw extruder simulation
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35. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (HVAC)
Where is CFD
used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing-HVAC&R
-Hydraulics-
Marine-Oil & Gas-
Power Generation
-Sports
Streamlines for workstation
ventilation
Particle traces of copier emissions
colored by concentration level fall
behind the copier and then circulate
through the room before exiting the
exhaust.
Mean age of air contours indicate
location of fresh supply air
Flow pathlines colored by
pressure quantify head loss
in ductwork
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36. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Cooling of transformers
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37. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Flow pathlinesand temperature distribution in a
fan-cooled computer cabinet.
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38. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Hydraulics)
• Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC&R
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
Total Discharge
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39. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Marine)
• Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC&R
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
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40. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Streamlines on a Submarine with the surface colored with Pressure
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•Sea structures
•Boots And ship design
•Under water vehicle design

41. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Oil & Gas)
• Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC&R
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
Flow vectors and pressure
distribution on an offshore oil rig
Flow of lubricating
mud over drill bit
Volume fraction of gas
Volume fraction of oil
Volume fraction of water
Analysis of multiphase
separator
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42. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Power Generation)
Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
Flow around cooling
towers
Flow in a
burner
-HVAC
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
Pathlines from the inlet
colored by temperature
during standard23
Flow pattern through a water
turbine.
operating conditions

43. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Computed flow in the runner
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44. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Flow through the turbine
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45. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Computed flow in the draft tube
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46. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Application of CFD in food industry
CFD to analyse the flow and performance of process equipment, such as
•Baking ovens
•Refrigerated display cabinets
•Stirred tanks
•spray dryers
•Heat exchangers
•some other equipment. In design and development,
CFD programs predict
•Fluid flow behaviour,
•Transfer of heat, mass (such as in perspiration or dissolution
•Phase change (such as in freezing, melting or boiling),
•Chemical reaction (such as combustion or rusting),
•Mechanical movement (such as an impeller turning, pistons, fans or
rudders)
•Stress or deformation of related solid structures (such as a mast
bending in the wind).

47. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Application of CFD in food industry: Cold storage.
Contoursofiso-temperaturesinthemostsensitiveplaneofarefrigeratedtruck
(a)withoutairducts(b)withairducts

48. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Where is CFD used? (Sports)
• Where is CFD used?
-Aerospace
-Appliances
-Automotive
-Biomedical
-Chemical Processing
-HVAC
-Hydraulics
-Marine
-Oil & Gas
-Power Generation
-Sports
Pressure distribution on an F1car

49. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Some more applications
Fluid flows around the boat
Temperatures on flame surface
modeled using LES and state-of the-art
combustion models
34
•Special Clothing Design (motor cycledriving
Garments, ventilated cap and hats)
•Shoes design (safety shoes)
•Furniture design
•Hajj

50. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Need of CFD
•Experimental costs are higher
•Experimental times are high
•Impossible to measure
•Experimental verification not
feasible
•Impossible to see/ visualize
•Flexibility

51. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Applications of CFD
•Mechanical Engineering Applications
•Fluid flow analysis
•FEA
•Mixing analysis (solid and solid metal alloys) (solid and gas foam),
Gas and solid) (liquid and gas fussy drinks) (gas and liquid) (liquid,
liquid petrol diesel) (gas and gas air)
•Aerodynamic analysis
•Automobile and engine
•Air-conditioning ,Heating, Cooling & ventilation
Industrial and Manufacturing Engineering Applications
•Fluid flow in Moulds & dies
•Process simulation
•Time and motion study

52. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Applications of CFD
Civil Engineering Applications
•Building/bridges and structures safety design ( against Floods And
Wind Storms)
•Canal
•Sewer design
Environmental Engineering Applications
•Weather and climate forecasting
Naval Architecture Applications
•Sea structures
•Boots And ship design
•Under water vehicle design

53. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Medical Applications
•Blood flow
•Medicine mixing
•Heart failure
•Brain Damage (bursting of blood vessels)
•Bones reconstruction.
•Tooth implants
General application
•Special Clothing Design (motor cycledriving Garments)
•Shoes design (safety shoes)
•Furniture design
•Hajj

54. DR. Muhammad Mahmood Aslam Bhutta Lahore ,Pakistan
Thank You