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Old   April 1, 2016, 09:11
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Joel Fuentes Tobin
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I am using Ansys Fluent to model an 11 stage Tesla Valve. I'm using the Response Surface Optimisation > Design of Experiments to try and optimise the geometry of the Tesla Valve. I have everything set up correctly such as my parametrisation, meshing, Set-Up etc... The issue I am having is whenever I click 'Update' to solve my 27 Design Points, it fails as I get these error messages

"received a fatal signal (Segmentation fault)"
"cx-restore-view: no views are stored"
"Init_Flow: invalid case"
"Update of the Solution component in Forward Flow for design point 1 failed: An error occurred in FLUENT when initializng the flow
An error occurred in FLUENT when initializng the flow"

I have no idea how to fix it, I thought a Segmentation fault was due to a lack of RAM on the computer, however if I reattempt it with Windows Task Manager opened, the CPU usage hovers around 70-80% and the Physical Memory usage stays between 50-70%, so I figured as it wasn't >90% then it shouldn't be the case.

Can anyone please help? I have a technical report due in two weeks and this project will take a few days to solve.
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Old   April 3, 2016, 06:04
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Cees Haringa
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I cannot help you pinpoint the exact error, but a segmentation fault can be due to any memory issue (not only a shortage of it). For example, it may arise because the solver tries to call non-initialized variables. Such issues occur easily when using user defined memory or scalars, because they are not initialized during the default routine as far as I know. Are you using any such parameters?

EDIT: from the message, it seems that in your case it may have something to do with an animation or so. Could that be the case?
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Old   April 4, 2016, 16:19
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Joel Fuentes Tobin
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Hey Cees, thank you so much for your reply!

Yeah I have 5 Geometric Input Parameters these are;

Geometric -
Pipe Width
Angle (Between the module and pipe)
Length (shortest straight line of the Module)
Radius (of the inner curve of the module)
Distance (between each module)

All 5 Geometric parameters are identical for all 11 individual stages of the Tesla Valve. I also have several manual output parameters for both the forward and reverse flows, such as;

Inlet Pressure
Outlet Pressure
Inlet Velocity
Outlet Velocity

Then the following parameters are manual calculations based on the above output parameters;

Forward Velocity Ratio
Reverse Velocity Ratio
Velocity Difference Ratio
Forward Pressure Difference
Reverse Pressure Difference
Diodicity (Reverse Pressure Difference/Forward Pressure Difference)

Are any of these 'non-initialized variables' or 'user defined memory or scalars' like you said? I'm really not overly competent with all the Fluent jargon. I hope this helps answer your question, if so any ideas how I can fix it?

Huge thanks
Joel

Last edited by jlft94; April 4, 2016 at 17:25.
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Old   April 4, 2016, 16:31
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Joel Fuentes Tobin
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Hey Cees

Just found the section for User Defined Memory and User Defined Scalars under the Parameters and Customisation branch, I can tell you that at the moment I have them both set to zero (mainly coz i dunno what they do) should I have them turned on or leave them off? Also I haven't set up any simulations either.

Thanks
Joel
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Old   April 5, 2016, 03:24
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Cees Haringa
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Well, if you don't use user defined scalars/memory, you should not set them to anything (the number of user defined memory locations is set to 0). And if you would use them, you would be familiar with the name - so I am quite sure these are not the problem.
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