Is boiling possible in SimScale?

[mriabov]

Sup SimScale,

I’m a new to CFD guy, who needs to simulate what seems to be the most complex piece of similation ever.

Is it possible to make boiling CFD computation in Simscale?

My setup:
A heater of 300W runs under water positioned on a flat 10 * 10 * 1.5cm closed chamber. Given that pressure is constant 1atm, how to calculate a force of vapor bubble pushing the upper surface of the chamber?

I hoped to sim before going to prototype.

Thanks everyone!

[shenoy]

Hey mriabov,

Thanks for posting on the forum.

Since phase change is currently not possible in SimScale, I believe that you won’t be able to simulate boiling of water or any other medium unfortunately.

However, from the open roadmap page you can suggest that such a feature is a added and our team will work on it on the next opportunity.

[jairogut]

CFD is very useful for some problems, but in this specific case, I think using it would be very difficult

1. If it is a chamber without moving walls, the vapour phase will push all the boundaries, which is basically calculated depending on the pressure (P = F/A).
2. The vapour pressure can be calculated using thermodynamic equations and constants, which will take into account the mass of the vapor phase (which depends on the energy transfered to the liquid, the time and the pressure itself).
3. As the vessel will increase its pressure with time, the latent heat of vaporization will change as well as the phase changing temperature. This would require either a 0-dimensional model to be run in a transient state or solving some differencial equations.

[mriabov]

Right. Would it be possible to at least simulate air bubbles appearing in a hot, very viscous water?

We can assume that the pressure will at some point run off elsewhere.

[jairogut]

I am not sure if SimScale has incorporated a two-phase Euler-Euler solver yet, which would be the appropriate solver type when dealing with bubble flows without boiling. Maybe someone from SimScale can answer this. If not, you could suggest that feature, but in the short term, you would need to work with OpenFOAM (which is the software SimScale is based on). The issue with OpenFOAM is that you likely need an expert to use it effectively.

[KevinGreen]

@jairogut

CFD is very useful for some problems, but in this specific case, I think using it would be very difficult

.

Yes, it is possible to simulate boiling and associated phenomena in SimScale, but it can be complex. SimScale supports multiphase flow simulations, which you can use to model boiling by setting up a CFD simulation with a multiphase model that includes water and vapor phases. To calculate the force exerted by vapor bubbles on the upper surface of your chamber, you’ll need to incorporate heat transfer and phase change modeling in your simulation. You’ll apply the heater power as a thermal boundary condition, set up the fluid domain with appropriate initial and boundary conditions, and use the multiphase flow model to capture the bubble formation and movement. Analyzing the results will give you the pressure distribution and forces on the chamber surfaces. Be prepared for significant computational demands and ensure that your setup is properly configured to handle these complexities. Writing a case study can be challenging, but this Write My Case Study: Expert Writers, Original Papers service provides students with the necessary support to produce high-quality work. The platform ensures that the case studies are original, well-researched, and aligned with academic requirements.

1. If it is a chamber without moving walls, the vapour phase will push all the boundaries, which is basically calculated depending on the pressure (P = F/A).
2. The vapour pressure can be calculated using thermodynamic equations and constants, which will take into account the mass of the vapor phase (which depends on the energy transfered to the liquid, the time and the pressure itself).
3. As the vessel will increase its pressure with time, the latent heat of vaporization will change as well as the phase changing temperature. This would require either a 0-dimensional model to be run in a transient state or solving some differencial equations.

Thanks for replying, I also want to know it. If I want to know more, I will ask by starting my own thread.

[igaviano]

Hi all, I think I missed this thread.

Simulation of bubble formation is indeed possible using our multiphase/multi-purpose solvers coupled with surface tension .

We have a validation case on that:

• Rising Bubble Multiphase Simulation | Validation Case | SimScale

Best,
Igor