grid independence

Dear community,

I am studying palabos, since I want to analyze the grid-independent of this library in problems of hydrodynamics. I run from the example poiseuille.cpp with different resolution values (8,16,32,64,128).

Through the file iostream.cpp ', I could see the speed profile at half of system, but when I put this graph, I plotted against the number of resolution, not against the system length.

And I can not to compare these graphs.

Can someone help me?, I attach the code’s part about profile.

if(iT%parameters.nStep(logT)==0){ plb_ofstream successiveProfiles("./tmp/Profile_velocity.dat"); Box2D profileSection(parameters.getNx()/2,parameters.getNx()/2, 0, parameters.getNy() -1); successiveProfiles << setprecision(4) << *multiply ( parameters.getDeltaX() / parameters.getDeltaT(), *computeVelocityNorm (lattice, profileSection) ) << endl; }