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Under relaxation factors for pressure and velocity

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Old   October 12, 2005, 23:11
Default Under relaxation factors for pressure and velocity
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Wasy
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Hello,

Do the under-relaxation factors for pressure and velocity always have to sum to unity?

Thanks.
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Old   October 13, 2005, 00:41
Default Re: Under relaxation factors for pressure and velo
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zxaar
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nope
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Old   October 15, 2005, 13:01
Default Re: Under relaxation factors for pressure and velo
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pUl|
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zxaar is correct. And for some more info on URFs check out this answer given by an engineer at Fluent (the fourth comment to be precise):

http://university.fluent.com/blog/in...&pb=1#comments
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Old   October 26, 2005, 08:41
Default Re: Under relaxation factors for pressure and velo
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Cyril
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Hello, I'm a french student. i've got to fill in the Under relaxation factors box. But I don't know what is really these factors. Can somebody help me ?

Thanks !

Cyril
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Old   November 19, 2012, 01:42
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Girish
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Quote:
Originally Posted by Cyril
;125527
Hello, I'm a french student. i've got to fill in the Under relaxation factors box. But I don't know what is really these factors. Can somebody help me ?

Thanks !

Cyril
Because of the nonlinearity of the equation set, it is necessary to reduce the change of a variable from one iteration to the next. This is referred to as under-relaxation. For example, if the pressure under-relaxation factor is 0.3, the change in pressure value from one iteration to the next will be restricted to 30% of the difference between the initial value and the newly calculated value.
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