how to define bc for a oscillating flow output?

itsqi7 · January 24, 2013, 22:55

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, 02:30

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

itsqi7 · January 26, 2013, 03:22

Quote:

Originally Posted by msaeedsadeghi

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, 16:37

Quote:

Originally Posted by msaeedsadeghi

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.
121.JPG
Thanks for ur kind help.

Regards,
itsqi7

msaeedsadeghi · January 27, 2013, 23:35

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

itsqi7 · January 27, 2013, 23:39

Quote:

Originally Posted by msaeedsadeghi

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?

January 24, 2013, 22:55	how to define bc for a oscillating flow output?	#1
itsqi7 Member jiaqi wang Join Date: Jan 2013 Posts: 36 Rep Power: 13	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

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January 26, 2013, 02:30		#2
msaeedsadeghi Senior Member SSL Join Date: Oct 2012 Posts: 226 Rep Power: 14	You should use pressure inlet for both outlet and inlet. For more configuration you should use a DEFINE_PROFILE udf.

January 27, 2013, 23:35		#5
msaeedsadeghi Senior Member SSL Join Date: Oct 2012 Posts: 226 Rep Power: 14	It's better to add a channel to inlet and outlet, could get a better results.