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 Robert March 3, 2008 12:57

phase change

Hello, I would like to simulate a flow, which has phase change, from water to vapor. I use the mixture/cavitation model. I calculate the vaporization pressure with a polynom. I use pressure inlet boundary condition for inflow, and pressure outlet for outflow. The outflow pressure lower, like the vaporization pressure. My problem: The fluent limit the pressure to the vaporization pressure and I don't know, why? If somebody know, please tell it to me :)

Thanks

 Robert March 5, 2008 03:42

Re: phase change

 Pavan March 5, 2008 11:02

Re: phase change

Thanks Robert. It was pretty much what I was doing. I was concerned about the difference I was seeing over flow time. But the error was less than 1.5% That still should not exist but I guess it could be numerical error or something. I guess I won't worry about it.

 Pavan March 5, 2008 11:03

Re: phase change

sorry responded in the wrong section!

 Syed Shabbar Raza March 7, 2008 02:03

Re: phase change

23.6.2 Wet Steam Flow Equations

The wet steam is a mixture of two-phases. The

primary phase is the gaseous-phase

consisting of water-vapor (denoted by the subscript v) while the

secondary phase is the liquid-phase

consisting of condensed-water droplets (denoted by the subscript l).

( and my dear u want to model inverse, i mean here fluent assume that the primary phase is steam, but in your case it is water and i can guess that u have given the boundary condition for water ( inlet condition),

so i think we should use inlet boundary condiition for outlet and vice versa

 Syed Shabbar Raza March 7, 2008 07:09

Re: phase change

for using wet vapors fluent have limitation of 273k to 647k, might be your temperature exceed this limits, that why it limits ur pressure

 tuce May 2, 2009 06:17

helpppp

would somebody help me pleasee?I try to simulate two phase flow (water
boiling )by cfd .but I could not manage it.I really need its tutorials.my mail address is tuceyilmaz1984@hotmail.com ıf somebody helps I will be very glad.tnanks by now.

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