Reply To: The choice of boundary conditions

[Marcin Nowak]

I would like to prepare a numerical model that would reliably reflect the experimental data. Which means:
1) impose boundary conditions as pressure-inlet and pressure-outlet, validate using experimental data: velocity time profile and deformations,
or:

2) impose boundary conditions as velocity-inlet and pressure-outlet, validate using experimental data: inlet pressure profile and deformations.

The solid material properties are tuned, using FEM-only analysis.

In the case 1) I receive the proper pressures at walls and proper deformations, but completely different velocities at the inlet.

In the case 2) I receive too low pressure at walls (and at the inlet) and therefore too small deformations. But velocities are proper, due to the imposet inlet-velocity BC.

I think that model 1) is better, but I am looking for the setting which will lead to the solution of all variables coincide with the experiment, i.e. including velocities.