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Xin Yan

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Show the regular access to external flow Set up a turbulent problem

Expressions

Additional choices for deal with the result

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A finite cylinder in a wind tunnel

L=1.5m W=1m H=1m D=0.1m h=0.3m D1=0.5m D2=0.5mAir at 25

Density: 1.185 [kg m^-3] Dynamic Viscosity:1.831e-5 [kg m^-1 s^-1]Inlet velocity:

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D

L

W

H

h

D2

D1

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Geometry: DesignModeler Pre-processor Mesh: CFX-Meshing

CFX-Pre

Solver CFX-Solver

Post-processor CFX-Post

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ANSYS workbench:DesignModeler (.agdb)

Modeling

1) Wind tunnel:

2) Cylinder: Cut material

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Create>Primitives>Box

Create>Primitives>Cylinder

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ANSYS workbench:DesignModeler (.agdb)

Modeling

1) Wind tunnel:

2) Cylinder: Cut material

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Create>Primitives>Box

Create>Primitives>Cylinder

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ANSYS workbench:CFX-Mesh

1) Specify regions

2) Set spacing for regions

3) Inflation mesh

4) Generate the surface &volume mesh

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ANSYS workbench:

CFX-Mesh

1) Specify regions

2) Set spacing for regions3) Inflation mesh

4) Generate the surface &volume mesh

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ylinder Plate

Spacing Max:0.005mMin:0.001m

Max:0.01Min:0.0037

Inflation 0.005 0.0075

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ANSYS workbench: CFX-Pre1) Create a domain

2) Set up boundary conditions

3) Set solver control

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ANSYS workbench: CFX-Pre1) Create a domain

2) Set up boundary conditions

3) Set solver control

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Outlet: outlet>average static pressure 0 PaWalls: wall>free slipCylinder & plate: wall>no slipInlet: inlet>normal speed>velocity profile

>Intensity=1%

Help: Expression language

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ANSYS workbench: CFX-Pre

1) Create a domain

2) Set up boundary conditions

3) Set solver control

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ANSYS Workbench: CFX-Solver

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Why?Increase accuracy

Where?

Near wall area whereyou are interested in.

How?

Insert inflated boundary.

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Inlet

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Assume 1/7th power law:

[1]http://www.see.ed.ac.uk/~johnc/teaching/fluidmechanics4/2003-04/fluids9/2-dboundary.html

[1]

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Outlet & Opening Outlet: the flow is predominantly directed out of the domain.

Opening: allows the fluid to cross the boundary surface ineither direction.

Wall No-slip: velocity of the fluid at the wall boundary is set to

zero.

Free-slip: the velocity component parallel to the wall has afinite value (which is computed), but the velocity normal to

the wall is zero.

Symmetry

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ANSYS Workbench: CFX-Solver

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ANSYS Workbench: CFX-post1) Contour and vector of velocity in the plane

of z=0.5m.

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ANSYS Workbench: CFX-post2) Streamline of velocity in the plane of y=1.5m.

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ANSYS Workbench: CFX-post3) Streamline of 2-D velocity (v&w) in the plane

of x=0.58m.

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ANSYS Workbench: CFX-post4) Contour of turbulence kinetic energy (k) and

vorticity (x) in the plane of x=0.58m.

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ANSYS Workbench: CFX-post5) Quick animation

Streamlines

Planes

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Finish the simulation Capture the picture of streamline with two

vortexes in the plane parallel to the plate.

Capture another picture which you areinterested in and give a brief introduction ofthis picture, include the plane location andthe feature in the picture.

Due day: 13/10/2010

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