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compressibility and cavitation!!

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Old   March 5, 2005, 22:37
Default compressibility and cavitation!!
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xhliu1
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I have a problem with cavitation. The pressure dependent density description for the liquid works fine as long as I do not activate cavitation. But when activating the cavitation I get NaN for the produced species in the first Iteration (although there is no cavitation at the beginning of the simulation at all).

As I using the cavitation model,density of the heavy fluid just can be set as a constant number.Can I using some method to solve this problem?

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Old   March 8, 2005, 13:07
Default Re: compressibility and cavitation!!
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Julien
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Old   March 8, 2005, 13:09
Default Re: compressibility and cavitation!!
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Julien
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Density of the heavy fluid is set constant by default. There is no other model in StarCD available at this moment.
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Old   March 9, 2005, 02:54
Default Re: compressibility and cavitation!!
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xhliu1
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Thank you very much!! xhliu
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Old   March 9, 2005, 04:51
Default Re: compressibility and cavitation!!
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carno
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I am also facing same problem with cavitation in 3.22. The run is starting but after some iterations it is coming out. I have relaxed the problem very much still that problem is not vanishing. Does anybody else also face this problem with cavitationin 3.22. In 3.15 same case use to run very fine.

One strange thing is that I see different heavy fluid viscosity than what I specified. xhliu1 pls check this in your run file.

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Old   March 9, 2005, 07:18
Default Re: compressibility and cavitation!!
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xhliu1
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carno,what I can say you is sorry,because I am using 3.15.
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Old   March 10, 2005, 06:07
Default Re: compressibility and cavitation!!
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carno
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Check your mesh. Hope the critical area has good quality cells.
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Old   March 14, 2005, 02:11
Default Re: compressibility and cavitation!!
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xhliu1
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It works nothing! I can do the case of compressibility and cavitation separately very well!
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Old   March 15, 2005, 06:49
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carno
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where such situation exists? I am just curious. U mean for vapour phase you are applying compressibility. I think only valid density setting is constant in this case. How u gave compressibility in cavitating flows.
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Old   March 15, 2005, 21:52
Default Re: compressibility and cavitation!!
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xhliu1
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Thank you very much foe the reply!

Do you mean I should neglect the compressibility in case of cavitation?

But,in this case,the density of oil varies much with variety of pressure in the flow!
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Old   March 16, 2005, 07:29
Default Re: compressibility and cavitation!!
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carno
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In other words STARCD is not capable of solving cavitation with change in heavy fluid density situation. Local support may guide you more on this.
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Old   March 16, 2005, 08:19
Default Re: compressibility and cavitation!!
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xhliu1
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Thank you!!

I have also see it in the reference of STARCD.But I want to see if there is another way to do this case.
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