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Old   March 18, 2008, 19:57
Default Speed sweep
  #1
Gustaf
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Let's say I want to run a number of identical simulations: the same mesh, same boundaries in all locations except the inlet velocity, which I'd like to sweep from some min speed to some max speed.

It seems to me right now to do this I have to write a batch script that generates CCL and mulitiple (very large!) .def files just to change that one parameter.

Shurley there must be a simpler way?

Thannk you, Gustaf
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Old   March 19, 2008, 05:29
Default Re: Speed sweep
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Steven
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As far as I know thats the way to do it I just did 66 different mesh and def files for my airfoil simulation. In your case though, as your just changing the boundary condition is it possible to run the simulation as transinet and have a velocity that is a function of time and then each time step would be a solution with a different velocity?

Might want to wait for other responses to see if thats a valid way to do it though!

Steve
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Old   March 19, 2008, 17:59
Default Re: Speed sweep
  #3
Chebeba
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I must say that I would have thought this type of analysis was a really common "bread & butter" type thing. It seems strange to me that it does not have better UI support.

Interesting suggestion with the transient solution. I read through the docs on transient. It seems it would make the problem more complex, since the solver would actually try to take the previous steps into account when the flow speed is increased. It appears to me that this adds computational complexity compared to solving a set of discrete steady state cases.
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Old   March 19, 2008, 18:06
Default Re: Speed sweep
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UnderwaterAlex
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If you want to take advantage of all the bells and whistles Ansys has to offer, you can probably do this using Design Explorer in an automated fashion. I have not used this product myself, but my understanding is that it is for exactly this sort of situation. Check online for more info.

Best of luck,

-Alex
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Old   March 20, 2008, 02:06
Default Re: Speed sweep
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Jonathan
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DesignXplorer works with the mechanical FEA tools. Not with CFX.
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Old   March 20, 2008, 11:15
Default Re: Speed sweep
  #6
UnderwaterAlex
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Really? I thought you could couple DX through workbench to run CFX simulations as well. In CFX Pre 11.0 SP1, if you right click on an expression, one of the options is "Use as DX Parameter." At the last Ansys Conference I went to (San Diego - April 2007) they discussed using DX for multiphysics/FSI as well. Of course, like I said, I haven't used it but my impression was you could utilize it in CFX through Workbench.

Sorry if I have misled.

-Alex
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