To improve the visualisation and the calculation of important values, we had to refine the mesh in y direction. In the refined meshes, there are 20 or 40 cells following the test case.
Different boundary conditions : inlet in red with velocity profile, outlet in green and symmetry in blue.
To verify that the simulation of a Poiseuille flow is good, two properties must be verified : the parabolic velocity profile and the pressure loss that must be linear and equal to a theoritical value calculated as following :
where Umoy is the initial value of inlet profile and Uaxe=1.5 Umoy in theory :
The results were good and we have this type of simulations :
We verify that we have a parabolic profile in y and that the pressure loss along the x-direction is equal to the theoritical one.
Considering the number of cells in the y direction, it is quite normal not to observe a "perfect" parabolic profile.
Indeed the axis velocity is almost equal to its theoritical value : 1.48E-3 instead of 1.5E-3.