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sudden drop in solver monitor

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Old   February 25, 2011, 03:27
Default sudden drop in solver monitor
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Ji Guozhao
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Dear all:
I was trying to simulate gas going across membrane process. the porous media separate the gas domain into feed side and permeate side. the feed pressure is as large as 200kpa. and the perm side is 0 pa. the permeability is very small so the resistance for gas passing through is large. I set velocity inlet as 0.0003 m/s, opening outlet with 0 pa.

why the iteration shows a sudden drop like the pic in attachment. although it converged, the result obtained is non sense.
so is there any one who can tell me why there is a sudden drop in solver monitor?
Kind regards
Ji Guozhao
g.ji@uq.edu.au
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File Type: jpg sudden drop.jpg (10.3 KB, 12 views)
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Old   February 25, 2011, 06:44
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Glenn Horrocks
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Try using double precision numerics.
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Old   February 26, 2011, 19:55
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Ji Guozhao
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Quote:
Originally Posted by ghorrocks View Post
Try using double precision numerics.
Excuse me Sir! can you tell me how to set double precision. is it in cfx pre?
with regards
Ji Guozhao
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Old   February 27, 2011, 06:34
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Glenn Horrocks
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Either in Pre or in solver manager (in advanced options).
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