phase change in CCM+
 

Hi
I was wondering if any of you had modelled a phase change in CCM+ and wether there a ready made macro for that?
Thanks

Phase change in ccm+
 

Please can you explain your question?
I have simulated a phase change in ccm+ with VOF-Model
I do not need a macros.

Rabat

PCM properties to be modelled
 

Hi rabat
I want to model the heating up of the material up to its melting temperature, the latent heat of fusion absorbed by the material, it's flow caracteristics while melting and once completely melt. I thought I'd need a macro to model the fusion heat, and the change in porosity and thermal conductivity when its melting. I am not aware of being able to do that straigth in 4.02
Thanks

Phase Change CCM+
 

Hi Rabat,
I have to simulate with CCM+ two fluids in contact at different temperature and pressure, and one of them have a phase change....can you help me to do this simulation???

Best Regards

P.Dino

What are your quetions?
 

of course, What are your quetions?


Hi Rabat,
I have to simulate with CCM+ two fluids in contact at different temperature and pressure, and one of them have a phase change....can you help me to do this simulation???

Best Regards

P.Dino[/QUOTE]

Hi Rabat,
I have never done any simulation with phase change, so if you can send me some lectures about CCM+ or FLUENT, or some example relating the setting of evaporation conditions, I will be very happy....
The problem is about a flow of a first fluid in another fluid at elevated temperature. The first fluid evaporate and I want to set the conditions related to evaporation process.
Can you Help me???

Best Regards

P.Dino

Hello Rabat,

I'm interested in a phase change problem too - condensation. Do you have any material on condensation modeling in STAR CCM+/STAR CD?

Thanks
Aroon

Hi, Rabat,
I have faced a problem when I do a simulaiton abou vapor condensation. After setted the corresponding parameters and conditions, an error information coming out as below:

SaturationPressure::getMaterialProperty(): property missing

Do you know what's the reason lead to this error?

Best Regards.

The error you mention provide from the fact that you has defined the droplet as secondary phase in the continua VOF phase interaction), you must define the first phase as liquid droplets and the secondary as the water vapor for example.

I know that my answer is late but maybe it will help someone.

Best regards,

Miki

Condensation
 

hello everyone,

i am trying to solve a simple problem of condensation using star ccm+ but i am unable to get the correct result.
i am working with condensation on vertical plate, i have used vof model and also the condensation and evaporation model supplied by software but the results doesnt shows condensation.

can anyone of you help me to solve this problem...

That is a known mystery of the last few years; many people have tried - but I haven't heard of anyone succeeding in this.
If you somehow manage to make condensation work - please post solution here.

According to other sources, there are two ways for simulating condensation.
1. fluid film for condensation at wall surfaces
2. thin film for condensation away from wall surfaces

Referring to this I would say that the VOF E/C-Model only computes phase changes between fluid-fluid interfaces.

hello mustopf,

have you tried for fluid film model for wall condensation...?? if so then can you please help me to obtain the results for wall condensation...

Well I am working on it. I got a multi-component gas to condensate on a wall. Can you give me a few more details about your scene? Do you only want to condensate a gas or a component of it or is there an additional phase change before?

Condensation
 

actually i m working for just simple condensation work to verify nusselt model using fluid film model... i am using star ccm+ software to solve this problem, my geometry is simple rectangular box (3d) one of the wall is having cold temperature and top is inlet and bottom is outlet and rest is adiabatic . i had chosen the fluid film model under this i have chosen two phases one is vapour and other is air for the gas multi component and in multi component liquid is water.

in this i have activated the evaporation and condensation model and added the connectivity

inlet condition of vapour and air is 375K and fraction i have choosen 0.8 for vapor and 0.2 for air.... cold wall temperature is 300K but their is no formation of fluid film on the wall...

actually i am also having dout in defining the species mass fraction in the physics... how to define it... or i have chosen wrong fraction

so can u help me to work with it or any of your suggestion how to handle it...

I would recommend to calculate the humidity in your area, it makes the definition of the mass fraction a lot easier.
Your settings for the film condensation are fine so far. You have to create a shell region for your cold wall and connect this shell to your film continuum. At this shell you define the cold temperature of your wall the same way you would do it in the Region. After doing this you should be able to define a scalar scene with fluid film thickness and as part you choose the defined shell.

I hope you get it to work. Otherwise I have to explain it more detailed

could you please give me the detail of humidity calculation to approach the mass fraction... any example... here is my mail id binit.kumar17@gmail.com , can you share your experience of your work on condensation through mail in detailed...

i will be thankful to you...

Can you please explain how you used VOF phase change? is there any example? I have tried to do it but I can only use it with multi-component fluids. I to use it with single component only.

Are you using multi-component ? can you tell me the physical model order you have?

I am sorry for my absence, I had some trouble with my projects.
You can calculate the humidity with the following formula: hum= P_part/p_sat
The saturation pressure is defined by the Antoine-equation. You can use the parameters from Star-CCM+. They are defined in the saturation pressure of your Fluid. The partial pressure is simply defined by absolute pressure*MoleFractionH2O. I never calculated the mass fraction for the humidity. There is a way in the documentation of Star-CCM+, but in my case it takes longer than just setting a parameter and initialize.

0.8 for vapor seems a little bit high. Saturated Air could be around 0.2-0.3 at 375K.