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 VSB December 4, 2006 05:23

CFX and cylindrical coordinates

Hi

As a simple example I have started with modeling laminar flow through a pipe

I have created a mesh in ICEM CFD in cartesian coordinates(I presume ICEM allows you to create geometries in cartesian coordinates only)

After exporting it to CFX, How should I specify the velocities and other details in cylindrical coordinates?

Also let me know if ICEM permits creation of geometry in cylindrical coordinates.

Thanks

VSB

 Joe December 4, 2006 08:33

Re: CFX and cylindrical coordinates

After exporting it to CFX, How should I specify the velocities and other details in cylindrical coordinates?

Create a new cylincrical CS in Pre.

 Robin December 4, 2006 13:38

Re: CFX and cylindrical coordinates

CFX actually gives you cylindrical coordinates (r and theta) about the Z axis of any coordinate system. If you pipe is aligned with the Z axis, you'll already have access to these.

If all you want is the ability to specify velocities in cylindrical coordinates, just pick this option in the boundary condition GUI. It will ask you for the primary axis, so you may still need to create a coordinate system if your pipe is not aligned with a global axis, but I suspect it is.

What exactly do you need the cylindrical coordinate system for?

Regards, Robin

 VSB December 7, 2006 11:02

Re: CFX and cylindrical coordinates

Hi Robin and Joe,

I would like to know one thing.

If I model a pipe flow problem using cylindrical coordinates and cartesian coordinates, will there be a difference in the solution values obtained in both the techniques?

I have been getting contrasting views from different people.

Thanks

VSB

 opaque December 7, 2006 11:16

Re: CFX and cylindrical coordinates

Dear VSB,

ANSYS CFX only works with cartesian coordinates.. You can input data in cylindrical coordinates, and they will be converted to their cartesian components.

Most 3D codes are in cartesian coordinates, and 2D codes offer an option for axisymmetric cases.

What is your main concern? mesh discretization of the curvilinear terms? The physics of the flow does not know anything about the mesh, or reference frame selected..

Opaque

 oewnce932c October 8, 2013 14:43

1 Attachment(s)
Hi;)
Do ANSYS CFX still accept only Cartesian coordinate system?
Trying to add cylindrical system, for some output data..but couldn't find it out;(