Hi @sjoshi it’s great someone continues this thread!
As @quequen seems to be a bit deeper and up-to-date with the topic of hull’s design – I had the lectures and some practice years back now – I’d still like to add something from me.
I’ll focus on your last outcomes as I assume these are the best one so far. So I took your animation, cut the very last frame and this is what I’ve got:
(Sorry if I missed it in text.) Roughly measuring the distance behind the hull is about ten times the length of a yacht. The width is more than five time the hull’s width – I like it. But what I don’t like and don’t understand is why there is such a small gap between domain inlet and yacht’s bow? Look at the picture above (and your earlier picture, orange one too). Didn’t you notice that? (Sometimes it happens that we miss obvious things )
I assume the water table is expected to be flat (no waves), but here we can see clearly some wave is forming in front of a bow. – The same phenomenon you can observe in your previous simulation (!) - I would say you should move the object further down the domain and I would keep the other dimensions as they are. It’s nice to read your discussion about wake shape, but don’t forget about what’s happening in front. BTW residuals go smooth and stable with it?
Also: the time step here seems to be 0.1 [s] (animation contains of 81 frames). It’s fine. But with domain size at 30 [m] and velocity 3.73 [m/s] the time of 8 [s] you set hardly covers (or even doesn’t) the time that a particle of water needs to travel from the inlet to the outlet. If you start your simulation with zero velocity it’s not enough.
You have written you had quadrupled the domain size. Personally I think it’s not the right way. Not at this point. First I’d like to get rid of that wave at the inlet, obtain smooth and undisturbed inflow and only then move my attention to the wake.
So please, if you could run this simulation in approximately the same domain, but move the object about two hull lengths back. You have the precise values, but I’d like to ask for domain and object placement like this:
And, if you start with zero velocity, I’d like to see results after at least 16, maybe even 18 seconds minimum.
Big PLUS for you for running this simulation with full hull, without symmetry.
Finally, could you paste in velocity and pressure fields at symmetry plane? @quequen mentioned something about shallow water and draught, so I’d like to see if there is any influence of domain bottom at it.