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-   -   HELP - Moving car simulation in fluent (http://www.cfd-online.com/Forums/fluent/28184-help-moving-car-simulation-fluent.html)

 Brad Wells January 30, 2001 19:54

HELP - Moving car simulation in fluent

I am currently trying to model the movement of a car through a tunnel here in Melbourne. In the simulation we are interested in looking at the piston effect for this tunnel, and how that relates to exhaust and other emissions. I am having trouble actually working out how to simulate a moving car in fluent with pressure inlet/outlet boundry conditions at the ends of the tunnel.

All of the moving reference frame / moving mesh approaches I have tried seem to move the air in the tunnel at the same speed as the moving reference frame, and keep the car stationary. What we need though is to have the air stationary and have the car moving. Moving wall approaches also do not work, as air velocities generated from this approach is often an order of magnitude too low.

Does anyone have any suggestions on how to get a moving car in a tunnel simulation?

 John C. Chien January 31, 2001 07:35

Re: HELP - Moving car simulation in fluent

(1). Are you sure that the code has the capability to do so? (2). You are talking about the moving boundary condition problem. I got the impression that they are considering the moving boundary condition in the future version of the code. (I am not sure, so it's a good idea to check with the support engineer first.)

 Trac January 31, 2001 23:34

Re: HELP - Moving car simulation in fluent

Hi Brad (another VPAC person!)

Do you want to model the car In the Wind Tunnel, or just a car? To model the car, you have the ground as a moving boundary, at the same speed as the airspeed. The car is stationary. It's the same theory as a wind tunnel, you move the air, keep the car still. In your case though, to move to a car-stationary system rather than air-stationary system, you need to now have the air at the same speed as the ground.

Trac.

 Kai Kang February 2, 2001 13:48

Re: HELP - Moving car simulation in fluent

This depends on the reference frame you are using when you looking at the results. In fluent, you can set these reference values.

If this is a straight tunnel, moving wall, or moving reference frame should resolve the steady case, if you are trying to see the transient simulation, you need to use sliding mesh...

 S.Manivasagam,B.Raja February 4, 2001 23:43

FSI using FLUENT

Dear Friends, Does any one know the procedure for simulating fluid structure interation in FLUENT.Let the domain of interest be " flow acting on a cantilever beam". Please help us. Thank You

 Joern Beilke February 7, 2001 15:44

Re: HELP - Moving car simulation in fluent

If your tunnel has a finite length you have to solve a moving mesh problem, since the car changes its position relative to the start and end of the tunnel.

This is a bit similar to the following example:

www.beilke-cfd.de/train.mpg

 sachindranitrkl February 27, 2012 03:14

how to create gemotry for in gambit for this type of dynamic mesh.

Quote:
 Originally Posted by Joern Beilke ;96038 If your tunnel has a finite length you have to solve a moving mesh problem, since the car changes its position relative to the start and end of the tunnel. This is a bit similar to the following example: www.beilke-cfd.de/train.mpg
plese send me sachindranit@gmail.com

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