Changing Boundary Condition TypesZones and zone types are initially defined inpre-processor.Boundary ConditionsXZoneTypeTo change zone type for a particular zonedefault-interiolinlet-ventfluidintake-faninletinterfaceDefineBoundaryConditions...orificemass-flow-inletoutletoutflowplateoutlet-ventplate-shadowpressure-far-fieldChoose the zone name in Zone listwallpressure-inletpressure-outletCan also select boundary zone using rightsymmetryvelocity-inletmouse button in the grid display.wallSelect new zone type in the Type listID7CloseSet...Copy....Help
4-6 ANSYS, Inc. Proprietary Introductory FLUENT Notes Fluent User Services Center FLUENT v6.3 December 2006 Changing Boundary Condition Types ◆ Zones and zone types are initially defined in pre-processor. ◆ To change zone type for a particular zone ⚫ Choose the zone name in Zone list. ◼ Can also select boundary zone using right mouse button in the grid display. ⚫ Select new zone type in the Type list. Define Boundary Conditions
Setting Boundary Condition DataBoundary ConditionsXZoneTypeExplicitly assign data in BC panelsdefault-interioiinlet-ventfluidintake-fanTo setboundary conditions forparticularzone:inletinterfaceorificemass-flow-inletChoosethezonename inZonelistoutletoutflowplateoutlet-ventClick Set... buttonplate-shadowpressure-far-fieldwallpressure-inletBoundaryconditiondatacanbecopiedfrompressure-outletWrite Profileonezoneto anothersvmmetryvelocity-inletOptionswallBoundary conditiondata can bestored andDefine New ProfilesIDretrieved from a file using TUI commands:CWrite Currently Defi7/file/write-bcSurfacesValuesSet...Copy...CloseHelpdefault-interiorStatic/file/read-bcinletPressDynamic PressureorificeBoundary conditions can also be defined byoutletAbsolutePressureplateTotal PressureUDFs and profiles.plate-shadowRelativeTotalPressurewallDensityDensityAllzone-surface-7Profiles can be generated by:Velocity MagnitudeXVelocityWriting a profile from another CFD simulationYVelocityZVelocityCreating an appropriately formatted text fileAxial VelocityRadial Velocitywithboundary condition data.Tangential VelocityRelativeVelocityMagnitudeWrite...CloseHelp
4-7 ANSYS, Inc. Proprietary Introductory FLUENT Notes Fluent User Services Center FLUENT v6.3 December 2006 Setting Boundary Condition Data ◆ Explicitly assign data in BC panels. ⚫ To set boundary conditions for particular zone: ◼ Choose the zone name in Zone list. ◼ Click Set. button ⚫ Boundary condition data can be copied from one zone to another. ◆ Boundary condition data can be stored and retrieved from a file using TUI commands: /file/write-bc /file/read-bc ◆ Boundary conditions can also be defined by UDFs and profiles. ◆ Profiles can be generated by: ⚫ Writing a profile from another CFD simulation ⚫ Creating an appropriately formatted text file with boundary condition data
Velocity InletVelocitySpecificationMethodMagnitude, Normal to Boundary区ComponentsVelocity InletZone NameMagnitude and DirectioninletVelocity profile is uniform by defaultMomentum Thermal Radiation Species DPMMultiphase UDIntendedforincompressibleflowsVelocity Specification Method Magnitude, Normal to BoundaryReference Frame AbsoluteStaticpressureadjuststoaccommodate一Velocity Magnitude (m/s] 5the prescribed velocity distribution.-constantTurbulenceTotal (stagnation) properties ofthe flowSpecification Method Intensity and Hydraulic Diameteralso varyTurbulent Intensity[2Using velocity inlets in compressibleHydraulic Diameter (m) 4flows can lead to non-physical resultsCan be used as a “velocity outlet"" byOKCancelHelpspecifyingnegativevelocity.Youmust ensurethat mass conservationis satisfied if multiple inlets are used
4-8 ANSYS, Inc. Proprietary Introductory FLUENT Notes Fluent User Services Center FLUENT v6.3 December 2006 Velocity Inlet ◆ Velocity Specification Method ⚫ Magnitude, Normal to Boundary ⚫ Components ⚫ Magnitude and Direction ◆ Velocity profile is uniform by default ◆ Intended for incompressible flows. ⚫ Static pressure adjusts to accommodate the prescribed velocity distribution. ⚫ Total (stagnation) properties of the flow also vary. ⚫ Using velocity inlets in compressible flows can lead to non-physical results. ◆ Can be used as a “velocity outlet” by specifying negative velocity. ⚫ You must ensure that mass conservation is satisfied if multiple inlets are used