Kelvin-Helmholtz instability
Forum rules
As this forum is intended to post modelling examples, for better clarity, posts may be edited, and questions may be removed in some cases once the parent is updated.
As this forum is intended to post modelling examples, for better clarity, posts may be edited, and questions may be removed in some cases once the parent is updated.
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Jean Deschodt
Kelvin-Helmholtz instability
A simplified Kelvin Helmholtz instability was simulated. Dry air filled up the upper half of the domain, and humid air the lower half. A 4% difference of density was assumed between the two gas. 2 m/s difference in velocity across the interface was fixed. The inlet velocity of the dry air was perturbed with a sinusoidal signal in order to generate the instability.
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Jean Deschodt
Re: Kelvin-Helmholtz instabilities
Files to reproduce the case with Code_Saturne 2.0-rc1 :
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- usiniv-f90.gz
- (2.91 KiB) Downloaded 1090 times
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- kelvin-med.gz
- (1.18 MiB) Downloaded 1132 times
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- instabilities-xml.gz
- (1.88 KiB) Downloaded 1115 times
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David Monfort
Re: Kelvin-Helmholtz instability
Hello Jean,
This is a really nice example here!
However, you might have better results with symmetries farther from the middle (haven't try though...). It seems you have some "blocking effect" due to the presence of the symmetries at bottom and top.
David
This is a really nice example here!
However, you might have better results with symmetries farther from the middle (haven't try though...). It seems you have some "blocking effect" due to the presence of the symmetries at bottom and top.
David
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Jean Deschodt
Re: Kelvin-Helmholtz instability
I redo the computation with a wider inlet. Indeed, it changes the flow a little. I redo also the set up without usini1.f90: everything was done by the GUI. I upload the new files below.
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- kelvin-xml.gz
- (1.93 KiB) Downloaded 1130 times
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- kelvin-helmholtz-med.gz
- (3.56 MiB) Downloaded 1145 times
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Claus Andersen
Re: Kelvin-Helmholtz instability
I thought the attached picture was relevant to this post went I came across it - I assume it's the described phenomena?
Regards,
Claus
Regards,
Claus
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