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Old   August 8, 2013, 07:02
Default Cylindrical Components Boundary Conditions
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Michal
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Do somebody can give clear instruction how understand cylindrical components from ANSYS point of view? Are they unit vectors or what?

I want to mimic swirling flow in injector of combustion chamber.
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Old   August 8, 2013, 08:03
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I do not understand what you are asking. Cylindrical coords for what? A local coord system? Or a 2D axisymmetric simulation? And what are you modelling in your injector - the flow inside the injector, the spray it creates or a combustion model?
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Old   August 8, 2013, 08:06
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Cylindrical comp. of flow direction as a result I want to have fuel well mixed with oxygen.
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Old   August 8, 2013, 08:09
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I still do not understand what you are asking. Have you completed a simulation and you want to extract the velocity of something in cylindrical corrds? If so what is something?
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Old   August 8, 2013, 08:14
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Please have a look:

http://postimg.org/image/4rqo0p3dt/ injector is modeled in this case as a point source...
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Old   August 8, 2013, 08:20
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I assume you are asking what form the cylindrical coords are. Yes, they are unit vectors. But I think you can enter any vector and CFX will take them as unit vectors anyway.
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Old   August 8, 2013, 08:24
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You are right, I was asking about it thx.
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Old   August 8, 2013, 08:32
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But how check influence of these components on swirling properties in the simplest way?
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Old   August 8, 2013, 13:38
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Very difficult to predict .
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Old   August 8, 2013, 14:16
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To do the topic more understandable I have attached image:

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Old   August 8, 2013, 18:47
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Your image was not attached and your question is still not clear.

But if you are asking how can you assess the importance of the direction vector on your simulation - you can do this with a simple sensitivity analysis. Just run a series of simulations with different direction vectors and compare the results. If there is no significant change in the result then the direction vector makes little difference.
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Old   August 9, 2013, 02:45
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Quote:
Originally Posted by ghorrocks View Post
Your image was not attached and your question is still not clear.

But if you are asking how can you assess the importance of the direction vector on your simulation - you can do this with a simple sensitivity analysis. Just run a series of simulations with different direction vectors and compare the results. If there is no significant change in the result then the direction vector makes little difference.
Thank you know it is: http://postimg.org/image/hj4w0kz45/
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Old   August 11, 2013, 18:26
Default swirl modeling
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Hello

I am facing the same issue. I want to generate a certain swirl in an axisymmetric slice section of a burner chamber. The question is then here, how is the flow direction related to the swirl strength and to the flow pattern?
Therefore, I need first of all to know the exact definition of theta component?
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