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September 27, 2015, 06:51 |
Diffuser reversed flow
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#1 |
New Member
T
Join Date: May 2015
Posts: 3
Rep Power: 11 |
Hi,
I know the subject of ‘reversed flow’ has been brought up several times, and I have diligently searched previous threads, however I cannot find a solution to my issue. I am trying to simulate an eductor that uses gas as the motive inlet, and a liquid phase as the suction inlet, both of which are pressure inlet BCs. Due to the study parameters, I have supersonic flow just following the nozzle, but I am continuing to get reversed flow at the end of the diffuser which has a pressure outlet BC. “reversed flow in XXX faces on pressure-outlet YY” So far I have tried the following solutions:
Model information:
Cheers, Macdhui |
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September 27, 2015, 12:42 |
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#2 |
Senior Member
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There are two possible causes:
1. Fluent gives the warning without reason (mostly for external flows), where velocity is almost zero. 2. For internal flow, best choice is to place the outer boundary faraway from the main flow. |
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October 8, 2015, 05:13 |
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#3 |
New Member
T
Join Date: May 2015
Posts: 3
Rep Power: 11 |
Thanks Sijal.
I have placed the outlet boundary 10x the internal diameter away from the exit of the diffuser, but I still get this issue. Should I extend it even further or do I need to investigate other sources of the reverse flow? Macdhui |
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October 8, 2015, 05:48 |
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#5 |
New Member
T
Join Date: May 2015
Posts: 3
Rep Power: 11 |
Sijal - I have PM'd you.
Many thanks |
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Tags |
eductor, jet, pressure outlet, reversed flow |
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