I am having problems getting the same result when I try to model the Hagen poiseuille flow as when I calculate it.
For more information on Hagen-Poiseuille en.wikipedia.org/wiki/Hagen%E2%80%93Poiseuille_equation
I have a 2d model with a rectangel width 0.1m and length 13m.
At the inlet I have a pressure of 2.52Pa using the pressure, no viscous stress option. And at the outlet 0Pa.
When I calculate the velocity profile for the flow I use the viscosity provided by COMSOL
eta=0.000547
and I calculate the velocity from
u(r)=(R^2-r^2)/(4*eta)*dp/dz
in cylindrical coordinates. R is the radius ie the half width of the rectangel. r i the variable radius.
dp/dz=1.9388Pa/m
I have attached a picture with the development of the flow and the calculated velocity profile. What am I doing wrong here?
For more information on Hagen-Poiseuille en.wikipedia.org/wiki/Hagen%E2%80%93Poiseuille_equation
I have a 2d model with a rectangel width 0.1m and length 13m.
At the inlet I have a pressure of 2.52Pa using the pressure, no viscous stress option. And at the outlet 0Pa.
When I calculate the velocity profile for the flow I use the viscosity provided by COMSOL
eta=0.000547
and I calculate the velocity from
u(r)=(R^2-r^2)/(4*eta)*dp/dz
in cylindrical coordinates. R is the radius ie the half width of the rectangel. r i the variable radius.
dp/dz=1.9388Pa/m
I have attached a picture with the development of the flow and the calculated velocity profile. What am I doing wrong here?