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TitlePresentazione Fluent
TagsMechanics Pressure Fluid Dynamics Navier–Stokes Equations
File Size1.8 MB
Total Pages48
Document Text Contents
Page 2

IntroductoryIntroductory FLUENTFLUENTNotesNotes
FLUENT FLUENT v6.0 v6.0 Jan Jan 20022002

Fluent User Services CenterFluent User Services Center

www.fluentusers.comwww.fluentusers.com

Starting FluentStarting Fluent

 From the class web page, go to From the class web page, go to Fluent Materials. Download the case,Fluent Materials. Download the case,

data and mesh files posted there.data and mesh files posted there.

 Go to Go to Start->ProgramStart->Programs->Fluent.Inc and choose Fluent 6.1. Choose thes->Fluent.Inc and choose Fluent 6.1. Choose the

2ddp solver.2ddp solver.

 From the File menu, choose Read Case/Data. Read the case and From the File menu, choose Read Case/Data. Read the case and datadata

files elbow.cas and elbow.dat. If you specify the name “elbow” Fluentfiles elbow.cas and elbow.dat. If you specify the name “elbow” Fluent

will read both automatically.will read both automatically.

 Explore Fluent‟s menu structure using this presentation as a Explore Fluent‟s menu structure using this presentation as a guide.guide.

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Introductory FLUENT Notes
FLUENT v6.0 Jan 2002

Fluent User Services Center

www.fluentusers.com

Setting Boundary Condition Data

 Explicitly assign data in BC panels.

 To set boundary conditions for particular zone:

 Choose the zone 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 file.

 file write-bc and 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.

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Introductory FLUENTNotes
FLUENT v6.0 Jan 2002

Fluent User Services Center

www.fluentusers.com

Convergence Difficulties

 Numerical instabilities can arise with an ill-posed problem, poor

quality mesh, and/or inappropriate solver settings.

 Exhibited as increasing (diverging) or “stuck” residuals.

 Diverging residuals imply increasing imbalance in conservation equations.

 Unconverged results can be misleading!

 Troubleshooting:

 Ensure problem is well posed.

 Compute an initial solution with

a first-order discretization scheme.

 Decrease under-relaxation for

equations having convergence

trouble (segregated).

 Reduce Courant number (coupled).

 Re-mesh or refine grid with high

aspect ratio or highly skewed cells.

Continuity equation convergence

trouble affects convergence of 

all equations.

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