Hello all COMSOL users!
I was solving a simple 2D Poiseuille flow problem on a rectangle domain. I use the "creeping flow" physical model with the "incompressible" option. And I just set the boundary condition of the inlet and outlet with two different pressure values with the options "pressure, no viscous stress" and "pressure" respectively. And I just leave the other two boundaries "no slip".
But I think I got wrong answers when solving this problem, because the pressure varies with not only x but also y near the inlet. This can be seen in the contour plot of pressure. However, as is well know, pressure should be just a function of x in this situation, and so the contour plot of pressure should be a set of vertical lines all over the domain.
So I am wondering why I got the wrong answer? Did I apply wrong boundary condition at the inlet? I got confused, because there is no other options relating to pressure can be chosen in the inlet setup menu.
Any comments will be grateful.
Pai Liu
I was solving a simple 2D Poiseuille flow problem on a rectangle domain. I use the "creeping flow" physical model with the "incompressible" option. And I just set the boundary condition of the inlet and outlet with two different pressure values with the options "pressure, no viscous stress" and "pressure" respectively. And I just leave the other two boundaries "no slip".
But I think I got wrong answers when solving this problem, because the pressure varies with not only x but also y near the inlet. This can be seen in the contour plot of pressure. However, as is well know, pressure should be just a function of x in this situation, and so the contour plot of pressure should be a set of vertical lines all over the domain.
So I am wondering why I got the wrong answer? Did I apply wrong boundary condition at the inlet? I got confused, because there is no other options relating to pressure can be chosen in the inlet setup menu.
Any comments will be grateful.
Pai Liu