They calculated velocity from Re. But for a laminar and hydrodynamically fully developed fluid flow, the velocity profile is parabolic. how to write an expression for it? In parabolic velocity profile v= v_max (1-(local radius/maximum radius)**2) how calculate v_max to write parabolic profile expression.
Inlet needs to be fully developed. It is one of the boundary conditions and the inlet temperature is 298.15k, fluid properties are a function of temperature . These are boundary conditions.