Finnally, I think it works. It is just that the results are not what I excepted. I was looking at the pressure near the inlet and the outlet (which are not exactly at the inlet and the outlet) and it is not at all the values that I set at the inlet and outlet. However, when I see the whole flow with Paraview, I see that the stream become very complexe and I think it is ok. Then, by switching between Bouzidi and Bounce Back, because of the complexity of the aorta stl file, the result is different. It schows that Bouzidi is better I think.
Thanks a lot for your help and I can share it if you explain me how to do. I am still a beginner.
Best regard
Sylvain