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Time is always zero

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Old   September 24, 2007, 16:04
Default Hello OpenFoam Users, I hav
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Kian Mehravaran
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Hello OpenFoam Users,

I have 1.4.1, compiled with single precision.
I noticed that when I use a deltaT lower than 1.0E-05, it is basically regarded as zero. In other words, time is always zero!
I checked the deltaT.value() in the code (sonicFoam), and it contains the correct value.

Any advice is appreciated,

Kian
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Old   September 24, 2007, 23:16
Default I compiled with double precisi
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Kian Mehravaran
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I compiled with double precision, and the problem is gone now.
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Old   September 25, 2007, 13:53
Default See Time.C around line 620.
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Mattijs Janssens
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See Time.C around line 620.

The problem in single precision is that there are only 6 significant digits. There is some truncation in operator++ to reach time 0 exactly which is probably too strict for your case.
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Old   September 26, 2007, 10:15
Default In the code segment you pointe
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Kian Mehravaran
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In the code segment you pointed to (the ++ operator), time is set to
value() + deltaT_
then it is forced to zero if its value is less than 10*SMALL or 1E-5, perhaps for aesthetics?!

I can't understand why it is not forced to zero in double precisions, when your deltaT is say 1E-8?
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Old   September 26, 2007, 10:24
Default OK, I was wrong about SMALL be
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Kian Mehravaran
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OK, I was wrong about SMALL being 1E-6 in double precision, that value is for single precision.

The actual value of SMALL is 1E-15 in dp.

I wanted to get rid of that if statement, but I'm going to stick with the dp version instead, since it is better tested.
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