[shameem]

Hi
I am simulating ship motions (3DOF, but concentrating on Roll studies). I am getting comparable results around the natural frequency of the ship model (compared with experiment) but after this the roll response is not matching with the experiment. The CFD results are decreasing with only a very small decrement after the natural frequency (let us say if the natural period is 1.6 sec, in 1.8 sec also am getting almost same result. But this was not the case with experiment) I tried with different models still the same problem persists. Can anyone suggest what may be the problem?
Thanks and regards!