Hello,

**Here is my situation:**

I am currently trying to find numerically the added mass coefficients on a completely immersed ellispoid, as a verification test for future studies with more complex geometries. Thoeretical results can be obtained considering a potential flow, hence I have made the hypothsis of incompressible laminar flow, with a slip wall condition on the solid as there I could not find any potential flow solver.

As a first step, I am trying to solve the case for a constant linear acceleration, so I went for a steady case study, with a time dependant velocity inlet. However, such a referential can not be considered as inertial, and a source term has to be added in the conservation of momentum equation ( more details in this paper https://www.diva-portal.org/smash/get/diva2:916575/FULLTEXT01.pdf).

**The problem is:**

It seems I can not define a time dependant speed accounting for momentum source. I have also tried to consider a transient study with solid linear body motion but I am facing the same problem.

Is my approach valid, and is there any way to solve this problem ?

*here is a link to the project* : https://www.simscale.com/projects/semilien/added_mass/

Thanks