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Overflow and Zero divide errors in compressible flow |
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April 23, 2014, 06:18 |
Overflow and Zero divide errors in compressible flow
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#1 |
New Member
Noukhez Ahmed
Join Date: Mar 2014
Posts: 9
Rep Power: 12 |
I have attached the error below in what I persist to get. I am trying to simulate a centrifugal compressor in compressible flow and keep encountering overflow, no matter what settings I alter. This is the main problem. Furthermore, in order to achieve better residuals, I have used incompressible flow allowing it to converge, then changing the flow to compressible and run from this point forward. However, the zero divide error arises. Please review the attached documents. I hope you can help. Many thanks.
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April 23, 2014, 07:17 |
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#2 |
Senior Member
Bharath kumar
Join Date: Apr 2009
Posts: 169
Rep Power: 17 |
I don't have experience in compressor CFD model. Still i had some questions.
1) Check your solver is reporting High Mach number (more than 2) warning while solving compressible flow.Is that OK? 2) Rotor domain minimum angle is 10.Is it possible to improve that? 3) Incompressible flow is a bad intial condition for a compressible flow problem. 4) Try less Pressure ratio first and gradually increase it to final value.It may help. |
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April 23, 2014, 10:13 |
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#3 |
Member
Kevin Hoopes
Join Date: Oct 2010
Posts: 43
Rep Power: 16 |
What Exit BC are you using? I have seen this alot when the compressor is trying to run off the map.
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April 24, 2014, 04:00 |
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#4 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143 |
This question is an FAQ: http://www.cfd-online.com/Wiki/Ansys...do_about_it.3F
Before diving into details I would check that the basics covered in the FAQ have been checked first. Because the first one (mesh quality) is almost always a MAJOR factor. |
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