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Old   February 5, 2016, 10:30
Default my problem
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yaseen
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Hellow every one, I modeled a spillway but error happen during running, as shown in attached images
http://www.cfd-online.com/Forums/att...1&d=1454682464
mesh new 2.jpg
mesh new 3.jpg
mesh new 4.jpg
mesh new 5.jpg
result.jpg
https://drive.google.com/open?id=0B3...m1FYUdZbnBySXc

Last edited by yaseen wsu; February 6, 2016 at 07:25.
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Old   February 6, 2016, 05:33
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Glenn Horrocks
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FAQ: http://www.cfd-online.com/Wiki/Ansys..._went_wrong.3F

Why are you using a moving mesh on a spillway simulation? This sounds unusual.
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Old   February 6, 2016, 07:34
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dear Glenn Horrocks thanks for your reply
I dont much know about moving mesh, only I used mesh adaption in CFX in order to capture free surface because I cannot refine entire model (lack of HP computer), but in the second run I removed mesh adaption, error does not occur but the solution does not convergence is it due to mesh quality or time scale, boundary condition... (because during run between each iteration said "a wall hass been at portion of out let boundary condition (at 73 of faces)"
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Old   February 6, 2016, 21:45
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There is an FAQ on the "A wall has been placed" warning as well: http://www.cfd-online.com/Wiki/Ansys...f_an_OUTLET.22

In my experience free surface models require very high mesh quality. Mesh adaption will not give you high enough mesh quality, especially if it is going a bit bezerk (as the negative volume error implies). So do not use mesh adaption.

The error you are getting on the no mesh refinement simulation is a sign of another different problem.
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Old   February 11, 2016, 06:29
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Dear Glenn Horrocks thanks a lot
I re run my model by using opening BC. at outlet, but for global initialized for inlet I entered velocity in X and Y direction, my inlet opposite to the direction of x and y axis is it required to enter as negative ? or not, also I specify inlet geometry height as the depth of water.
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Old   February 11, 2016, 06:35
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I do not understand your question. Can you please explain it more carefully, and post an image of what you mean.
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Old   February 11, 2016, 13:38
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Quote:
Originally Posted by ghorrocks View Post
I do not understand your question. Can you please explain it more carefully, and post an image of what you mean.
thanks for your reply,
my question is that first as shown in fig. one direction of inlet opposite to the X-Y axis, so in global initialization put value of velocity (u, v) in negative or positive? as shown in figure one
another question is " during running my model only ( u.v.w, RSM and P RSM) are appear unlike picture three (means does not contain mass of water and air) as well as I used RANS eq. (mass and momentoum)" thanks
https://drive.google.com/open?id=0B3...zRudXFhYnA2Vkk
https://drive.google.com/open?id=0B3...G5ULTNURlZ1NUk
https://drive.google.com/open?id=0B3...G5pcjZBcVVPNGs
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Old   February 11, 2016, 17:31
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I do not have permission to see those files. Please attach them in the forum rather than posting links.
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Old   February 12, 2016, 04:31
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http://www.cfd-online.com/Forums/att...1&d=1455265573
http://www.cfd-online.com/Forums/att...1&d=1455265621
http://www.cfd-online.com/Forums/att...1&d=1455265660
pictures one and two about inlet boundary condition, and third picture is not my simulation but my problem is during running iteration my simulation does not contain (mass of air and water ) means continuity equation only contain momentum eq.
best regards
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Old   February 12, 2016, 05:43
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Your global initial condition of a u velocity does not look a good idea. It is not a good approximation of the real flow. I would just use a zero velocity for everything.

Also make sure you define your inlet pressure taking into account the reference conditions. Have a look at the tutorial problem flow over a bump to see how they do it.
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Old   February 13, 2016, 02:43
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thanks a lot my problem is about to solve, but I have another problem, I created my geometry by many parts (because of complex geometry to facilitate mesh refinement) this interface prevent running model how can I removed the effect of these interface (I cannot delete it by right click on them)
best regards
http://www.cfd-online.com/Forums/att...1&d=1455345400
http://www.cfd-online.com/Forums/att...1&d=1455345418
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Old   February 13, 2016, 06:27
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You will need to remesh to remove the interfaces.
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Old   February 13, 2016, 07:03
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Quote:
Originally Posted by ghorrocks View Post
You will need to remesh to remove the interfaces.
remesh? in mesh (ANSYS ICEM), can you explain more clear
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Old   February 13, 2016, 11:51
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dear Glenn, I deactivated the interface but the problem is repeated, I read all previous threads about this case, I can solved this problem by create one solid geometry but I donot want like this because I want to refine each part separately.
thanks for your reply
best regard
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Old   February 14, 2016, 05:00
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ghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the rough
So it sounds like your problem is a meshing problem, not a CFX problem. Try the ANSYS geometry and meshing forum.
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Old   February 14, 2016, 09:54
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thanks for your reply
but my problem related to CFX because I only (un check) automatic create interface only
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Old   February 14, 2016, 17:42
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In that case I do not understand what you are asking. Post post some images and a clear explanation of what you are asking.
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Old   February 15, 2016, 11:55
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ok, my question is clear, my model is spillway, when I run my model as one solid part no problem, but my model consist three parts as shown in fig. (easier meshing) problem of (3 isolated region) appear, (as in CFX there is option to define pressure level, no slip wall.... but I dont want to define it because my geometry has one inlet and outlet so I dont know pressure at that location) how to remove this isolated region.
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http://www.cfd-online.com/Forums/att...1&d=1455551246
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Old   February 16, 2016, 00:37
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You need to mesh it as a multibody part or use interfaces to connect the mesh regions together.
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