Hi @youssef_bouzyad, thanks for posting on the forum and welcome to the SimScale Community 
Your model seems too complex for a straightforward analysis, I would strongly advise that you clean it up and defeature before running a simulation. Here are some general guidances on how to do that:
It also seems you haven’t created a flow region for your model, which is a crucial step in performing these sorts of analysis.
Our users also tend to agree that running 2-3 introductory tutorials before going to their own models is also very helpful in getting up to speed with SimScale: SimScale Tutorials and User Guides | Cloud-Based CAE | SimScale
Cheers
Igor