question about simulation of falling water film

mengyue1 · September 27, 2009, 01:41

Hello all,

I am studying evaporative cooling of a falling water film along a heated wall in the presence of counter-current air flow. The system is a rectangle channel with one sidewall heated and water falling along the heated wall, forming a water film, meanwhile, air is blowed to the channel at the bottom.

My initial thoughts are: Firstly create a rectangle channel and then create a face inside the channel, split the channel to two volumes with the face: one is channel for water flow and the other for air low; correspondingly, the top face is separated into two parts: one is the inlet of water and another is the outlet of air; the bottom face is similar to the top face, one is the outlet of water and the other is the inlet of air. I define the face used to separate the channel as interface. And I plan to use VOF model. Is that correct? I mean, in fact, I do not know the depth of the falling film, I just know the mass flow rate of water and the inlet velocity of air, so I do not know where I can define the interface, and it is said that VOF can automatically find the interface, so that means my definition of interface is meaningless?

Wow, I am so puzzled as a freshman using Fluent, any one has some useful suggestions for my question? Regards, mengyue1

mengyue1 · September 27, 2009, 07:13

hi, anyone can give some adivce? Thank you...

Quote:

Originally Posted by mengyue1

Hello all,

I am studying evaporative cooling of a falling water film along a heated wall in the presence of counter-current air flow. The system is a rectangle channel with one sidewall heated and water falling along the heated wall, forming a water film, meanwhile, air is blowed to the channel at the bottom.

My initial thoughts are: Firstly create a rectangle channel and then create a face inside the channel, split the channel to two volumes with the face: one is channel for water flow and the other for air low; correspondingly, the top face is separated into two parts: one is the inlet of water and another is the outlet of air; the bottom face is similar to the top face, one is the outlet of water and the other is the inlet of air. I define the face used to separate the channel as interface. And I plan to use VOF model. Is that correct? I mean, in fact, I do not know the depth of the falling film, I just know the mass flow rate of water and the inlet velocity of air, so I do not know where I can define the interface, and it is said that VOF can automatically find the interface, so that means my definition of interface is meaningless?

Wow, I am so puzzled as a freshman using Fluent, any one has some useful suggestions for my question? Regards, mengyue1

Boreas · March 30, 2014, 11:16

Hi Mengyue1,
I have the same kind of questions, I am trying to model free falling water in air. Did you find answers for your question?

September 27, 2009, 01:41	question about simulation of falling water film	#1
mengyue1 New Member mengyue Join Date: Sep 2009 Posts: 20 Rep Power: 17	Hello all, I am studying evaporative cooling of a falling water film along a heated wall in the presence of counter-current air flow. The system is a rectangle channel with one sidewall heated and water falling along the heated wall, forming a water film, meanwhile, air is blowed to the channel at the bottom. My initial thoughts are: Firstly create a rectangle channel and then create a face inside the channel, split the channel to two volumes with the face: one is channel for water flow and the other for air low; correspondingly, the top face is separated into two parts: one is the inlet of water and another is the outlet of air; the bottom face is similar to the top face, one is the outlet of water and the other is the inlet of air. I define the face used to separate the channel as interface. And I plan to use VOF model. Is that correct? I mean, in fact, I do not know the depth of the falling film, I just know the mass flow rate of water and the inlet velocity of air, so I do not know where I can define the interface, and it is said that VOF can automatically find the interface, so that means my definition of interface is meaningless? Wow, I am so puzzled as a freshman using Fluent, any one has some useful suggestions for my question? Regards, mengyue1

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
time step for unsteady film cooling simulation	Janendra Telisinghe	FLUENT	0	December 11, 2007 07:14
VOF model of water film	Pathway	FLUENT	1	July 21, 2007 08:33
Liquid film of water on an inclined surface	Dr. Daniel Gubler	Main CFD Forum	0	August 24, 2004 06:50
Terrible Mistake In Fluid Dynamics History	Abhi	Main CFD Forum	12	July 8, 2002 10:11
Question concerning about the flow simulation of a fan in an engine room.	ghlee	Main CFD Forum	3	October 21, 1998 08:05

March 30, 2014, 11:16		#3
Boreas New Member Bora Join Date: Dec 2010 Posts: 8 Rep Power: 15	Hi Mengyue1, I have the same kind of questions, I am trying to model free falling water in air. Did you find answers for your question?