Simplified Physical and Simplified Physical and Simulation Modeling of Simulation Modeling of

Building OccupantsBuilding Occupants

A seminar in A seminar in ““Experimental and CFD Benchmark Studies of Experimental and CFD Benchmark Studies of Indoor Flow around Thermal ManikinsIndoor Flow around Thermal Manikins””ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Prepared by Vladimir Vukovic and Dr. Jelena SrebricPrepared by Vladimir Vukovic and Dr. Jelena SrebricThe Pennsylvania State UniversityThe Pennsylvania State University

Presented by Dr. Atila Presented by Dr. Atila NovoselacNovoselacThe University of Texas at AustinThe University of Texas at Austin

22January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

OutlineOutline

BackgroundBackgroundHeat flux ratio for human simulatorHeat flux ratio for human simulatorGrid (in)dependenceGrid (in)dependenceResults and discussionResults and discussionHeat transfer coefficientsHeat transfer coefficientsConclusionsConclusionsFuture work Future work

BackgroundBackgroundHeat flux ratio for human simulatorHeat flux ratio for human simulatorGrid (in)dependenceGrid (in)dependenceResults and discussionResults and discussionHeat transfer coefficientsHeat transfer coefficientsConclusionsConclusionsFuture work Future work

33January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

BackgroundBackgroundKato laboratory, University of TokyoKato laboratory, University of Tokyohttp://www.cfdhttp://www.cfd--benchmarks.combenchmarks.comBenchmark Tests for a Computer Simulated Person (Nielsen et Benchmark Tests for a Computer Simulated Person (Nielsen et al. 2003)al. 2003)

44January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Measuring PolesMeasuring Poles

PIV

Temperature and velocity (L1, L2, L4, L5)Temperature and velocity (L1, L2, L4, L5)PIV (~ L3)PIV (~ L3)

55January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

OutlineOutline

BackgroundBackgroundHeat flux ratio for human simulatorHeat flux ratio for human simulatorGrid (in)dependenceGrid (in)dependenceResults and discussionResults and discussionHeat transfer coefficientsHeat transfer coefficientsConclusionsConclusionsFuture work Future work

66January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Y

X

HumanSimulator 2

Simulator 1Human

Inle

t

Pole 4

Pole 3

Pole 2

Pole 1

Source 4

Source 3

Source 2

Source 1

Heat Flux Ratio for Human SimulatorsHeat Flux Ratio for Human SimulatorsCritical Simulation Parameters for Critical Simulation Parameters for Accurate CFD Predictions of Contaminant Accurate CFD Predictions of Contaminant Dispersion from Indoor Point Sources Dispersion from Indoor Point Sources ((HuHuet al. 2005)et al. 2005)

77January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Qc:Qr=3:7 Qc:Qr=7:3

Thermal:Thermal: Simulation ResultsSimulation ResultsConvection vs. Radiation (Convection vs. Radiation (Qc:QrQc:Qr))

88January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

OutlineOutline

BackgroundBackgroundHeat flux ratio for human simulatorHeat flux ratio for human simulatorGrid (in)dependenceGrid (in)dependenceResults and discussionResults and discussionHeat transfer coefficientsHeat transfer coefficientsConclusionsConclusionsFuture work Future work

99January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Grid (in)dependence Grid (in)dependence -- TemperatureTemperature

On 2.4GHz Pentium 4, 1GB RAMOn 2.4GHz Pentium 4, 1GB RAM

and 20,000 iterationsand 20,000 iterations180,000 cells 180,000 cells 26h computations26h computations655,000 cells 655,000 cells 84h computations84h computations

1010January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Grid (in)dependence Grid (in)dependence -- VelocityVelocity

1111January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

OutlineOutline

BackgroundBackgroundHeat flux ratio for human simulatorHeat flux ratio for human simulatorGrid (in)dependenceGrid (in)dependenceResults and discussionResults and discussionHeat transfer coefficientsHeat transfer coefficientsConclusionsConclusionsFuture work Future work

1212January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Simulation ModelSimulation ModelSimplified human manikin simulationsSimplified human manikin simulations

1313January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Simulation DataSimulation DataTotal Heat Flux = 76 WTotal Heat Flux = 76 WManikin Heat Flux = 22.8 WManikin Heat Flux = 22.8 WRadiation Heat Flux = 53.2 W + ? (through Radiation Heat Flux = 53.2 W + ? (through ““adiabaticadiabatic”” walls)walls)Simulation Domain: Simulation Domain: X x Y x Z = 56 x 62 x 62 X x Y x Z = 56 x 62 x 62 ≅≅ 215,000 cells215,000 cellskk--εε turbulence simulation modelturbulence simulation model20,000 iterations20,000 iterationsPHOENICS 3.6.1 CFD simulation softwarePHOENICS 3.6.1 CFD simulation software

1414January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Temperature ResultsTemperature ResultsSide viewSide viewFront viewFront view

1515January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Temperature ResultsTemperature Results

1616January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Velocity ResultsVelocity Results

1717January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Velocity ResultsVelocity Results

1818January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

DiscussionDiscussion

Diffuser boundary conditionsDiffuser boundary conditionsFlow rate measurementsFlow rate measurementsDiffuser design Diffuser design –– geometrygeometry

Thermal boundary conditionsThermal boundary conditions““AdiabaticAdiabatic”” wall temperatureswall temperatures

⇒⇒ Heat transfer coefficientsHeat transfer coefficients

1919January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

OutlineOutline

BackgroundBackgroundHeat flux ratio for human simulatorHeat flux ratio for human simulatorGrid (in)dependenceGrid (in)dependenceResults and discussionResults and discussionHeat transfer coefficientsHeat transfer coefficientsConclusionsConclusionsFuture work Future work

2020January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Heat Transfer CoefficientsHeat Transfer CoefficientsConvection coefficientConvection coefficient

((AwbiAwbi and Hatton 1999; and Hatton 1999; NovoselacNovoselac et al. 2005)et al. 2005)

airsurface

convective

TTq

h−

=

2121January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

OutlineOutline

BackgroundBackgroundHeat flux ratio for human simulatorHeat flux ratio for human simulatorGrid (in)dependenceGrid (in)dependenceResults and discussionResults and discussionHeat transfer coefficientsHeat transfer coefficientsConclusionsConclusionsFuture work Future work

2222January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

SummarySummary

The following CFD parameters were The following CFD parameters were investigated:investigated:

grid resolution grid resolution convective to total heat flux ratio from convective to total heat flux ratio from human simulatorhuman simulator

““Critical Simulation Parameters for Accurate CFD Predictions of CCritical Simulation Parameters for Accurate CFD Predictions of Contaminant ontaminant Dispersion from Indoor Point Sources,Dispersion from Indoor Point Sources,”” Annals of Occupational HygieneAnnals of Occupational Hygiene

2323January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

ConclusionsConclusions

Steady state simulations vs. Real buildingsSteady state simulations vs. Real buildings

Dynamic simulationsDynamic simulationsParticularly appropriate for contaminant Particularly appropriate for contaminant simulationssimulationsUse simple human simulators (manikins), butUse simple human simulators (manikins), butAccurately determine boundary conditionsAccurately determine boundary conditions

Heat transfer coefficientsHeat transfer coefficients

2424January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

OutlineOutline

BackgroundBackgroundHeat flux ratio for human simulatorHeat flux ratio for human simulatorGrid (in)dependenceGrid (in)dependenceResults and discussionResults and discussionHeat transfer coefficientsHeat transfer coefficientsConclusionsConclusionsFuture workFuture work

2525January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Flow visualization V, T, and C measurements

Future WorkFuture Work

2626January 25, 2006January 25, 2006 ASHRAE 2006 winter meeting, ChicagoASHRAE 2006 winter meeting, Chicago

Questions?Questions?Dr. Jelena SrebricDr. Jelena SrebricDepartment of Architectural EngineeringDepartment of Architectural EngineeringPenn State UniversityPenn State University

Dr. Atila Dr. Atila NovoselacNovoselacDepartment of Civil, Architectural and Environmental EngineeringDepartment of Civil, Architectural and Environmental EngineeringUniversity of Texas at AustinUniversity of Texas at Austin

EE--mail: mail: jsrebric@psu.edujsrebric@psu.eduhttp://http://www.engr.psu.edu/jsrebricwww.engr.psu.edu/jsrebric//

EE--mail: mail: atila@mail.utexas.eduatila@mail.utexas.eduhttp://http://www.ce.utexas.edu/prof/novoselacwww.ce.utexas.edu/prof/novoselac//