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

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March 30, 2014, 11:16		#3
Boreas New Member Bora Join Date: Dec 2010 Posts: 8 Rep Power: 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?