[KevinMcTaggart]

I'm getting unexpected forces and motions for a ship in steady flow, free to heave and pitch. Using X 40 3 (Triangle based integration from the geometrical representation), here are some unexpected behaviours:
N 40 1 (2nd-order Adams-Bashforth) - No output forces or motions
N 40 2 (2rd-order TVD Runge-Kutta) - Output time for forces is 1.5 times actual value
N 40 3 (3rd-order TVD Runge-Kutta) - Similar problem to N 40 2
N 40 4 (3rd-order TVD Runge-Kutta low storage) - Output forces appear to have very strange cyclical behaviour every 3 time steps (e.g., drag forces are 0.99, 0.72, 0.60, 0.99, 0.72, 0.60, ...)

[Chalwwz]

Hi, thanks for testing out the different temporal schemes, however, the discrepancies could be a result of other setups as well. If you may, you could share the control.txt and ctrl.txt and other supporting files like stl, exp. so we can give a test.

[KevinMcTaggart]

I attach the input files control.txt and ctrl.txt. The zipped STL is too big at 600 kb. Is there a way to send a larger file?

[valgrinda]

Hi Kevin,

just wondering, which version of REEF3D are you using?

[KevinMcTaggart]

Sorry for my delayed reply on this. I'm now back to using Reef3D. I'm now using DiveMesh 24.05 and Reef3D 24.08. The force computations are now working generally well, with the exception of simulations often stalling, which I'll post separately.