bubble model

shahin.59 · July 15, 2009, 01:39

I am working on modeling and simulation of film boiling formation on hot rod when submerging in water. I use flow3d models so that use the adiabatic bubble model with heat and mass transfer. through, I use Clausius-Clapeyron model and found thermodynamic data which need for this model such water saturated pressure, latent heat vapor, accomodation coefficient and etc. then i enable the cavitation model for initiation of bubble, the result of model processing is not logical. For example the bubbles form an different place, but we excepted that bubble form only on hot surface of rod, also the pressure was not logical. I think there are any problem in cavitation properties in physics section also I have not confident on accomodation coefficient (I examined with 0.1 and 0.05 values). Would you please guide me for this problem and where are there any mistake for this model.

stefmascio · July 16, 2009, 10:00

the "thermal bubble with phase change" model would probably work better than the cavitation one.
I think the cavitation model generates the bubbles only where the pressure is below the cavitation pressure that you give, without looking at the temperature.

shahin.59 · July 16, 2009, 10:08

the "thermal bubble with phase change" can't simulate the initiation of bubble formation, we want model generation of bubble in a hot rod.
what can we do?

stefmascio · July 20, 2009, 10:17

I think the "thermal bubble" is a good model to simulate that. Many companies use it to model thermal bubbles in inkjet printers, where the bubble of air is generated inside the fluid starting from a hot surface.
But maybe somebody other more expert in inket simulation can confirm this.

July 15, 2009, 01:39	bubble model	#1
shahin.59 New Member shahin Join Date: Apr 2009 Posts: 8 Rep Power: 17	I am working on modeling and simulation of film boiling formation on hot rod when submerging in water. I use flow3d models so that use the adiabatic bubble model with heat and mass transfer. through, I use Clausius-Clapeyron model and found thermodynamic data which need for this model such water saturated pressure, latent heat vapor, accomodation coefficient and etc. then i enable the cavitation model for initiation of bubble, the result of model processing is not logical. For example the bubbles form an different place, but we excepted that bubble form only on hot surface of rod, also the pressure was not logical. I think there are any problem in cavitation properties in physics section also I have not confident on accomodation coefficient (I examined with 0.1 and 0.05 values). Would you please guide me for this problem and where are there any mistake for this model.

July 16, 2009, 10:00		#2
stefmascio Member Stefano Join Date: Mar 2009 Posts: 59 Rep Power: 17	the "thermal bubble with phase change" model would probably work better than the cavitation one. I think the cavitation model generates the bubbles only where the pressure is below the cavitation pressure that you give, without looking at the temperature. 6863523 likes this.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Simulation of a single bubble with a VOF-method	Suzzn	CFX	21	January 29, 2018 00:58
Superlinear speedup in OpenFOAM 13	msrinath80	OpenFOAM Running, Solving & CFD	18	March 3, 2015 05:36
Bubble Number density model	CFDUSERIN	CFX	1	November 9, 2011 09:50
3D bubble model	ekh95	FLOW-3D	4	April 29, 2009 19:09
algebraic slip model with stirred suspension?	Manuel Krause	CFX	0	April 15, 2005 09:10

July 16, 2009, 10:08		#3
shahin.59 New Member shahin Join Date: Apr 2009 Posts: 8 Rep Power: 17	the "thermal bubble with phase change" can't simulate the initiation of bubble formation, we want model generation of bubble in a hot rod. what can we do?

July 20, 2009, 10:17		#4
stefmascio Member Stefano Join Date: Mar 2009 Posts: 59 Rep Power: 17	I think the "thermal bubble" is a good model to simulate that. Many companies use it to model thermal bubbles in inkjet printers, where the bubble of air is generated inside the fluid starting from a hot surface. But maybe somebody other more expert in inket simulation can confirm this.