Validate my mesh
 

Hi.

I have a circular horizontal pipe with a 90 degree bend. The first thing I want to do is to run simulation with just pure water at low velocities.

How do I validate my mesh?

Hi,

May be you can try to do a mesh independency study, that is increase your mesh resolution and plot the solution for a variable of interest versus 1 over your number of nodes, and see if there is a linear variation.
That variable of interest can be pressure drop across the bend, or shear stress on wall, or anything you are interested in, and be careful that for some variables it is very harder to achieve mesh independency than the others.