I'm trying to generate velocity profile in cylindrical tube (3D, laminar flow module) containing water. I expected it to be parabola shape of velocity profile along the axial direction with zero velocity on the wall (I set the wall as no slip). However, I see the right side of the tubing wall does not reach to zero velocity. Also, the velocity values that I get from comsol is not matching well with the theoretical value as shown in the attached plot. Could you tell me how to improve the velocity profile value from comsol? I already tried finer mesh, but it didn't really help.
P.S. Overall I connect this laminar flow module with heat transfer module. I use the velocity values from the laminar flow module in the heat transfer module to see the temperature gradient along the z-direction by varying the flow rates.
P.S. Overall I connect this laminar flow module with heat transfer module. I use the velocity values from the laminar flow module in the heat transfer module to see the temperature gradient along the z-direction by varying the flow rates.