Using Simulation Motion, has anyone simulated or investigated design parameters in boat dynamics? Specifically, a buddy of mine is interested in determining "...at what roll angle the boat will sustain and still be self-righting unless taking-on water...". Apparently some design variables called "meta-center", "center of bouyancy" and CG come into play, here. I have not done any of this type of analysis, so any suggestions for software to use for an application like this is appreciated. This buddy of mine does not want to model fluid flow or gas/liquid interfaces - he's just interested in somehow using rigid bodies, springs, masses and dampers such as what Simulation Motion offers. Thanks for any suggestions.
Hi Tony,
I did something on this many years ago, and the challenge is really understanding the buoyancy variation with the position & orientation of the boat.
If there is a known variation of bouyancy force (location and magnitude) with roll angle, it is easy to represent using a force and moment. That is a big if though.
One thing I would try, is using 3-D contact to approximate the buoyancy force. The way 3-D contact works is it is a function of penetration. in other words it relies on the interfering volume and applying a reaction force at the center of the interfering volume based on the distance to the nearest free surface. So for example, let's say the volume of the hull below the waterline puts a center of volume at 200mm below the surface. The contact force is a function of this depth times the stiffness which would just be density of water times gravity.
This will ignore any rotational resistance you may have with the hull rolling, but should make an interesting simulation. I don't have time at the minute to give it a go, but let me know if this helps.
Cheers,
Ian