Yes, we can. Technically, there are other models that determine the phase change from water to steam. But VOF still tracks the ratios of each phase. I have seen this investigated for predicting cavitation of propeller blades. Honestly, CFD predicting phase change is something I need to read more about.
0.1m is 4inches ? That sounds like a very large distance especially if 6 to 12 cells are stacked. That would be a transition zone of 1.2m. Should that read 0.1mm?
The distance is correct. We do want a transition zone with enough vertical height to capture the waves generated. I say 1.2 m as a starting point, but it depends on the wave height. 0.1 m resolution depends on the flow conditions. You can frequently go to a smaller cell size near the body. Again, it depends on the flow conditions.
@@punkisinthedetails1470 This also exposes the practical side of CFD. Of course, we want higher resolution. But a dense refinement on the free surface can quickly make the simulation too large. Mesh density is often driven by available computer resources, just as much as the simulation physics.
hey nick, I am an Australian university postgrads student i am doing my thesis where, i need to set the concentration of dust in the air(34microgram pre meter cube).How can i do that in the euralian langrangian method.
The Courant number is still the best bet, since volume fraction propagates at the same rate as fluid velocity. However, Courant number changes depending on the mesh size in each region. If you are worried about timestep for a VOF simulation, base your Courant number on the mesh size at the fluid transition. All that said, if you are modeling a scenario that is effectively steady state, the simulation will likely remain stable at very high Courant numbers. I've pushed mine as high as Co = 2 in some simulations.
Hello , Nick sir. I really enjoyed your videos. I am looking for some guidance of implementing wake-integration method ( far-field method) to calculate induced drag on a wing. Could you share some information on it. It is really intressting and the maths behind it is really challanging. Not many can solved it out.
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
![[CFD] Eulerian Multi-Phase Modelling](/img/n.gif)
Sir, can you please make a video for people who are attending for interview for scientist posts?(for naval architects)
How about using VOF for water-steam interaction? can we model water phase change using this?
Yes, we can. Technically, there are other models that determine the phase change from water to steam. But VOF still tracks the ratios of each phase. I have seen this investigated for predicting cavitation of propeller blades. Honestly, CFD predicting phase change is something I need to read more about.
@@DatawaveMarineSolutions thanks for the instant response. 👍
0.1m is 4inches ? That sounds like a very large distance especially if 6 to 12 cells are stacked. That would be a transition zone of 1.2m. Should that read 0.1mm?
The distance is correct. We do want a transition zone with enough vertical height to capture the waves generated. I say 1.2 m as a starting point, but it depends on the wave height. 0.1 m resolution depends on the flow conditions. You can frequently go to a smaller cell size near the body. Again, it depends on the flow conditions.
@@DatawaveMarineSolutions ah with waves that makes sense. I thought the smeared thickness was 1m.
As a side note these are possibly the best clips of their kind.
@@punkisinthedetails1470 This also exposes the practical side of CFD. Of course, we want higher resolution. But a dense refinement on the free surface can quickly make the simulation too large. Mesh density is often driven by available computer resources, just as much as the simulation physics.
hey nick, I am an Australian university postgrads student i am doing my thesis where, i need to set the concentration of dust in the air(34microgram pre meter cube).How can i do that in the euralian langrangian method.
Hi Nick, it is a very useful video. I have a doubt, on what basis one can decide the timestep of simulation while doing VOF.
The Courant number is still the best bet, since volume fraction propagates at the same rate as fluid velocity. However, Courant number changes depending on the mesh size in each region. If you are worried about timestep for a VOF simulation, base your Courant number on the mesh size at the fluid transition.
All that said, if you are modeling a scenario that is effectively steady state, the simulation will likely remain stable at very high Courant numbers. I've pushed mine as high as Co = 2 in some simulations.
@@DatawaveMarineSolutions Well said, then I will stick with Courant number. Thank you ✌️
Hello , Nick sir. I really enjoyed your videos. I am looking for some guidance of implementing wake-integration method ( far-field method) to calculate induced drag on a wing. Could you share some information on it. It is really intressting and the maths behind it is really challanging. Not many can solved it out.
I'm not very familiar with that method. Afraid that I can't offer much help with your question. Good luck in your search.