Wake/Foam simulations of various hulls

[waaazoo]

I'm not sure I ever posted this video done 1 year ago. Please let me know what you think about it.
It was done with Maya/PhoenixFD/Vray

https://vimeo.com/362306683

cheers

[JezUK]

Superb !

I've done a couple of simulations and I found the learning curve pretty steep as well as the whole process of making settings and testing being very slow.

Maybe just me.

I'd love to be at your level

[francomanko]

yeah i always wanted to get into fluids but i dont think i have the patience What sort of simtimes are you looking at for those ?

[waaazoo]

Hi,

Thanks Jez and Francomanko !
@Jez: Yeah, you have to do a lot of simulations, with different cases, to get a feeling about the settings. At some point, you quickly get an idea about what to change to make your simulation better. I have now a quite large library of cases, with different hull sizes and speeds, which helps me to get a quicker result. But there are always cases where you have to test around. It's definitely something where you have to test step by step, and this takes time.
@francomanko: I think that sim times, overall, where always around 1 to 2 min per frame. In all my testing (usually I'm simming over 1500 to 1800 frames, for finals), some sims were finished in 24h, but some took 4 days to complete. It gets better now with FD4, and you definitely need a node with fast RAM, fast CPU, and Fast hard drive to speed up the simulation. It can make huge differences.

[fixeighted]

They're really great... the smoothest, most realistic examples I've seen on this forum.

[waaazoo]

They're really great... the smoothest, most realistic examples I've seen on this forum.

Oh, thank you so much for your kind words.

[olika]

Boat wakes yeay!
Very very good waaazoo ! Love the fast one the most for sure! as you know i was working on the same the last weeks

Can't resist to ask you a question. When i simmed the hull with good speed ( i think i was even a bit under 30 knots) i really had a hard time to prevent the splashes from going crazy in the beginning of the wake.
Just comes to my mind when i see yours and your splashes are nice in shape of the wake. Was it something that popped up too while working on it? I tried many things to influence exactly that and as it always like this in phoenix, everything did a bit to something haha but i did not had the feeling i got the correct control over it. I.e. i really increased the air drag of the splashes to prevent them going to high.

[waaazoo]

Boat wakes yeay!
Very very good waaazoo ! Love the fast one the most for sure! as you know i was working on the same the last weeks

Can't resist to ask you a question. When i simmed the hull with good speed ( i think i was even a bit under 30 knots) i really had a hard time to prevent the splashes from going crazy in the beginning of the wake.
Just comes to my mind when i see yours and your splashes are nice in shape of the wake. Was it something that popped up too while working on it? I tried many things to influence exactly that and as it always like this in phoenix, everything did a bit to something haha but i did not had the feeling i got the correct control over it. I.e. i really increased the air drag of the splashes to prevent them going to high.

Hi Olika,

Thanks a lot. The high speed movement is always tough to setup, and I was not even completely satisfied with it. I will open the scene in the next days and I'll try to give you some hints. With what SPF did you simulate ?
Before even thinking about Foam and Mist, you should first get a nice looking result on the Wake and Splashes. I'm always starting by tweaking these two items.

[olika]

waaazoo Hi and thanks for reply.
It's a balance of all those factors i guess and yeah i'm up for a chat to try to demystify it
Svetlin.Nikolov invited to join!

Beginning with the wake and splashed i observed the following:
When the hull cuts the fluid in the front, looking at reference pics of a real example, i was not really able to control the velocity that pushes the fluid to the left and to the right in a good way.
Raising the influence of the hull in the properties settings kind of exaggerated the "cut" of the fluid overall if you know what i mean but not really the power going left and right. Raising the influence above 2 gave me then some strange results in the back of the hull, the fluid starts to get dragged with boat.

I assume this is one the reasons i had a hard time getting the splashes under control because they're going of in full angle from water surface to the hull. But in my case the hull is shaped in a special way that in real life even when the boat is fast, all splashes are going underneath the bumper in the back of the boat. And this was very hard to achieve. Therefore velocity of the fluid and then splashes should go more to direkt left and direct right instead of going up so much also.

Also interesting thread to follow concerning wakes with speed, same problems in the end?:

https://forums.chaosgroup.com/forum/...ive-body/page2

[Svetlin.Nikolov]

Yo guys, if you have any scenes that you can share here or privately to support at chaosgroup dot com, please do, so we can see first hand what happens and be able to tell exactly what needs to be done. Usually crystal-balling it either works in the first couple posts in a thread, or if it's not solved by that point, a scene would be most helpful.

Cheers

[olika]

Svetlin.Nikolov glad you asking! i take your offer. And for everybody else having some good insights or willing to share some tips, i will pay you a free beer on the next real total chaos, i promise!

[Svetlin.Nikolov]

Got it, thank you! Starting sim right now...

[Svetlin.Nikolov]

olika , just to be on the same page - I assume 04_Wake_V2 is the scene where splashes are going crazy, right?

[olika]

morning Svetlin.Nikolov
Saying going crazy would be a bit to hard.
It's more about keeping the splashes more down. When you observe the fluid wake, it's not going up so much, that's fine but splashes rises way more up. That's what i try to understand, do you know what i mean?

Here's a pic of a real life example. You can see nicely how it is working in real life. All the fluid, splashes and foam stay under the blue line of the hull. With some knots of speed i was not able to reproduce this behavior as splashes tends heavily to also move upwards.

[waaazoo]

hmm, I can't remember a scene where I had splashes going (too much) upwards. With foam I had these problems, but not with splashes.
I will open my fast moving boat scene now and see what settings I have for splashes.