Difference between 2D and 2D axisymetric
Hello,
Im solving a flow through circular pipe. I am specifying pressure drop. When I use a axisymetric case, I get the velocity as per the Hagen Poiseuille Equation. But when I try to solve it using a 2D case it gives me velocity exactly twice of the axisymmetric case. Or simply put the avg. velocity which I am getting after running a 2D case is twice as what I should get from the Hagen Poiseuille Equation. Where can I possibly go wrong while simulating these two cases? Thanks. Varad |
Or simply put the avg. velocity which I am getting after running a 2D case is twice as what I should get from the Hagen Poiseuille Equation.
|
2d axisymmetric simulates a cilindrical pipe, 2d simulation a square/rectangular duct; what are your boundary conditions?under reference values what is the value for "depth"?
Daniele |
Reference value for depth is 1..
pressure inlet and pressure outlet with no slip conditions on the walls.. |
Quote:
|
Thank you guys for ur replies..
|
Quote:
Daniele |
No, this is incorrect. 2D models are infinitely long in the spanwise direction (Z axis, which you are not modelling). Any geometry that has a finite span, or does not have a perfect cylindrical cross section at all stations along its length must be modeled in 3D.
Stu |
Quote:
However I meant that if you are assigning for example an inlet velocity of 1 m/s and you have set a depth of 1 m with the inlet edge 0,2 m long your resulting flowrate will be 0,2x1x1 m3/s. For sure you are not modeling z interactions. Daniele |
All times are GMT -4. The time now is 20:48. |