For the boundary conditions, what do you know? The outlet pressure set to zero relative pressure is good. Do you know the inlet mass flow rate? How did you choose the velocity value of 0.05 [m/s]? Keep in mind if you put a uniform inlet velocity in there will be a larger pressure drop as the flow tends to the parabolic shape. If there is a long section upstream, maybe defining this inlet velocity parabola using Named Expressions.

But all that is for later. Before we sit down in front of the computer we need to do hand calculations to get a good estimate so we can accurately model the problem. (Plus we need to show all that time in the Universtiy was not wasted 🙂 ) Use what you learned in your Fluid Dyanmics class to calculate the Reynolds Number (validate the flow is laminar), compute the pressure drop (remember old Moody’s diagram?), plus all the correlations for the bends. Then you have a “good” estimate of what your pressure drop will be. This will give you, in this case, a very good data point that you can use to validate your CFD model.