1D axisymmetric equation based modelling basics

I am pretty new to comsol. I need to model a 1d axisymmetric problem of fluid flow at the moment and develop the model further. I cant find the fluid flow physics for 1D. so i decided to try equation based modelling.

Here are the eqautions i modelled using a pde

It is a simple couette flow model between to concentric cylindersof radii 0.0238 and 0.0064m




I am always getting last time step not converged.
Do you know what boundary conditions i should use for pressure.

Thank you