[ODE] Underwater vehicle simulation

[Brian London]

I am somewhat new to ode but I do know a bit about fluid dynamics (no expert here either).  I believe, however, that the answer to your question depends entirely on the level of accuracy you are trying to obtain.  If a simple shift of Reynolds number (i.e., from low speed air to low speed water) is all you are looking to simulate then you should be able to simply add a drag force to each of your objects proportional to the square of the velocity of the object.  To build on this a little more, you could apply drag forces such that the geometry of the object is taken into consideration. For example,

F = kA.v * |v|

where F is the force, k is a constant, A is a vector of surface areas (Ax is the x surface area,etc.), "." is a dot product, v is the velocity vector in the body centered reference frame and |v| is the speed  

If you want to consider lift and added mass, things become very complicated very quickly.  See http://en.wikipedia.org/wiki/Navier-Stokes_equations as an example.  For most games a simple addition of drag forces should be enough.

-Brian


> Hi everybody;
> I want to make a underwater vehicle simulator.
> How can i simulate water friction and dragging in ODE?
> And i want you ask a quesion. Do you think is ODE a good choice for
> underwater simulator? Have a good day...