[Sachin m]

I am working on calculation of water resistance on the hull of a ship. But I could not find a way to output the drag force values. I have been using a function in contolDict which reads as below:


libs
(
"libOpenFOAM.so"
"libforces.so"
);
functions
{
forces
{
type forces;
functionObjectLibs ("libforces.so");
outputControl timestep;
outputInterval 10;
patches (hull_patch0);
pName p;
UName U;
rhoName rhoInf;
log true;
rhoInf 1025*alpha1*100;
cofR (0.25 0.007 0.125);
}


Does this function output the force upto the water level of the hull or the complete hull?

[Ingenieur5]

Hi there,
I have the same task and used the force calculation accordingly. The results seem to be lower than tank test results. The reason I guess is that I am using the bare hull without appendages and without the influence of the propellers. So I am simulating really a towing experiment.
Is there a possibility to add additional resistance to the coefficients for above mentioned things?
Also: What need the center of rotation be like? normally it should be the longitudinal center of the actual waterline to judge about trim, or not?
Hope not to be the only one facing these problems....