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Main Menu bar

Global Control

Operation toolpad

Command line Description window

Graphical User Interface (GUI)

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Topology in GambitVolume

meshFace mesh

Edgemesh

Volume

Faces

EdgeVertex

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Geometry Creation

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Geometry Creation ACIS - geometry engine ("kernel")

z Provides tools for bottom-up creation by: Vertex: Add, Grid Snap, etc. Edge: Line, Arc, Ellipse, Fillet, B-spline, etc. Face: Wire Frame, Sweep, Net, etc. Volume: Wire Frame, Sweep, Face Stitch, etc.

z Provides tools for top-down creation by Face Primitives: Rectangle, Circle, Ellipse Volume Primitives: Brick, Cylinder, Sphere, etc. Volume/Face Booleans: Unite, Subtract, Intersect Volume/Face Decompose: Split

z Geometry creation typically involves use of all tools.

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Geometry Creation (3) Color Identification

z Connected Vertices and Edges are colored according to the highest order entity to which they are connected. To.

z The coloring scheme is: Vertex (white) Edge (yellow) Face (light blue) Volume (green)

Undo/Redo:z 10 levels of undo by default.

Undoes geometry, meshing, and zoning commands. Description window provides command to be undone

when mouse is passed over undo button.z Left click to execute visible button operation.z Right click to access options.

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Mesh Generation

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Design and Create the Grid

quadrilateraltriangle Quad/hex or tri/tet?

Grid resolution?

Sufficient computer memory?hexahedrontetrahedron

prism/wedgepyramid

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Edge Meshing Edge meshing form

z Picking

z Grading Single-sided grading Symmetric grading Asymmetric grading

z Spacing Interval Count % of edge length Interval Sice

z Special characteristicsz Options

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Face Meshing - Quad Examples

Quad: Map

Quad: Submap

Quad: Tri-Primitive

Quad: Pave

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Volume Meshes - Hex Examples Hex: Map

Hex: Submap

Hex: Tet-Primitive

Hex: Cooper

Hex: Stairstep

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Inputs to the Solver

GUI commands have a corresponding TUI command. Journal/Transcript write capability.

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Topology in Fluent Cell = control volume Face = boundary of a cell Edge = boundary of a face Node = grid point Zone = grouping of

nodes, faces, and/or cellsz Boundary data => face zones.z Material data and source terms => cell zones.

node

face

cell

cell center

Simple 2D mesh

face cell

node

edge

Simple 3D mesh

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Reading Mesh: Zones

inlet

outlet

wall

orifice(interior)

orifice_plate and orifice_plate-shadow

Fluid (cell zone)

Default-interior is zone of internal cell faces (not used).

Example: Face and cell zones associated with Pipe Flow through orifice plate.

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Fluid Flow and Heat Transferz Momentum, Continuity, and Energy Equationsz Radiation Models

Turbulencez RANS based models

including k-, k-, and RSM.z LES

Species Transport Volumetric Reactions

z Arrhenius finite-rate chemistryz Turbulent fast chemistry

Eddy Dissipation, Non-Premixed, Premixed, Partially premixed

z Turbulent finite-rate chemistry EDC, laminar flamelet

Surface Reactions

Models in Fluent 6 (1)

Pressure contours in near ground flight

Temperature contours for kiln burner retrofitting.

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Multiphase Flowsz Discrete Phase Model (DPM)z Volume of Fluid (VOF) model for

immiscible fluidsz Mixture Modelz Eulerian-Eulerian and Eulerian-

Granular Modelsz Liquid/Solid and Cavitation Phase Change Models

Flows involving Moving Partsz Moving zones

Single/Multiple Rotating Reference Frames Mixing Plane Model Sliding Mesh Model

z Moving and Deforming Mesh User-Defined Scalar Transport

Models in Fluent 6 (2)Gas outlet

Oil outlet

Inlet

Water outletContours of oil volume fraction in three phase separator.

Pressure contours for squirrel cage blower.

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Solver Enhancements: Grid Adaption Grid adaption increases cell resolution in Fluent Fluent adapts on cells listed in register.

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Solver Enhancements: Parallel Solver

With 2 or more processes, Fluent can be run on multiple processors.

Multiprocessor machine, or network of machines.

Mesh can be partitioned manually or automatically.

Partitioned grid for multi-element airfoil.

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Choosing a Solver

The Segregated (implicit) solver should be first choicez Less memory.z Flexibility.

The Coupled solvers are recommended if a strong inter-dependence exists between density, energy, momentum, and/or species.z Coupled-Implicit solver is recommended.z Coupled-Explicit solver only for unsteady flows with time scale around acustic

time scale e.g., tracking transient shock wave

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Discretization (Interpolation Methods) Interpolation schemes for the convection term:

z First-Order Upwind Schemez Power Law Schemez Second-Order Upwind Schemez Quadratic Upwind Interpolation (QUICK)

FLUENT interpolation schemes for Face Pressure:z Standardz Linearz Second-Orderz Body Force Weightedz PRESTO!

Pressure-Velocity Couplingz SIMPLEz SIMPLECz PISO (iterative & non-iterative)

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Convergence and Accuracy

At convergence:z Solution no longer changes.z Overall mass, momentum, energy, and scalar balances are achieved.z Monitor Residuals, relevant key variables and overall mass balance

A converged solution is not necessarily a correct one.z Use the second-order upwind discretization scheme for final results.z Ensure that solution is grid-independent:

Graphical User Interface (GUI)Topology in GambitGeometry CreationGeometry CreationGeometry Creation (3)Mesh GenerationDesign and Create the GridEdge MeshingVolume Meshes - Hex ExamplesInputs to the SolverTopology in FluentReading Mesh: ZonesModels in Fluent 6 (1)Models in Fluent 6 (2)Solver Enhancements: Grid AdaptionSolver Enhancements: Parallel SolverChoosing a SolverDiscretization (Interpolation Methods)Convergence and Accuracy