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-   -   how to define bc for a oscillating flow output? (https://www.cfd-online.com/Forums/fluent/112269-how-define-bc-oscillating-flow-output.html)

itsqi7 January 24, 2013 23:55

how to define bc for a oscillating flow output?
 
Hi,

The output is an oscillating one which has large volumn output and then little volumn reversed flow. I defined the oscillating boundary as 'outflow' but it seems an error as 'reversed flow in 4 faces on outflow 6'.
Could anyone told me which type I should define this bc? Thanks.

Itsqi7

msaeedsadeghi January 26, 2013 03:30

You should use pressure inlet for both outlet and inlet. For more configuration you should use a DEFINE_PROFILE udf.

itsqi7 January 26, 2013 04:22

Quote:

Originally Posted by msaeedsadeghi (Post 404141)
You should use pressure inlet for both outlet and inlet. For more configuration you should use a DEFINE_PROFILE udf.

Thanks for ur reply. I'll try that.

itsqi7 January 27, 2013 17:37

1 Attachment(s)
Quote:

Originally Posted by msaeedsadeghi (Post 404141)
You should use pressure inlet for both outlet and inlet. For more configuration you should use a DEFINE_PROFILE udf.

Hi, Saeed. I tried to use pressure inlet but the warning still happened. I think maybe FLUENT thought there is no fluid beyond the inlet and outlet, so when there is backflow it reports. Can I define, as I suppose, there is infinite fluid at the other sides of inlet and outlet?
My pump structure is as following.
Attachment 18535
Thanks for ur kind help.

Regards,
itsqi7

msaeedsadeghi January 28, 2013 00:35

It's better to add a channel to inlet and outlet, could get a better results.

itsqi7 January 28, 2013 00:39

Quote:

Originally Posted by msaeedsadeghi (Post 404426)
It's better to add a channel to inlet and outlet, could get a better results.

Thanks. By the way, how could I define that channel?


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