In the initialization pannel, in some of the fluent tutorials I have found that you often mention the compute from box to be some velocity inlet. what is the reason behind it? what if we dont mention this particular parameter?

can you explain the problem?

problem is really simple where water is coming in from an inlet and has the pipe has two branches as the outlet .. the geometry is not that important i guess .. but my question was about the way solution is found out ..

why do we have to mention compute from in the initialization pannel?

you can start from know velocity field or start from zero condition. If you know the velocity at inlet and initialize the domain with that value, it would converge fast.....