Hi to Everyone, i do a simulation with the deforming mesh but the solver give me the error of the subroutine cvolsec because it makes negative volume. do you know why? the node numer have to be the same in every mesh? How can i do this? i have to simulate a gear pump

Thanks

Hi,

Exactly what the error says - your mesh has turned inside out and you have elements with a negative volume. To debug these errors, turn all CFD simulation off (eg use expert parameters (solve fluids = f, solve turbulence = f) etc and write out the mesh to a results file every timestep. You can then see exactly how the mesh is deforming and hopefully spot the error.

Modelling a gear pump will be tricky with deforming mesh as you have to squash the mesh down to the very small clearance as the rotors engage. It will be tricky to do this without getting negative volume elements.

Glenn Horrocks

ok, the solver makes a crash file when it try to change the first mesh with the second, i use the subroutine, i post the error file.Help me My problem is that : how can i make the mesh for the second , third,fourth etc step. i want to use fortran subroutine like tutorials 20. but i have lot of trouble to make the mesh of the next step of one