I am writing code to understand the pressure correction algorithm in a cylindrical coordinate system and using axi-symmetric approximation to solve the flow through corrugated pipes for highly viscous fluids. I have solved it in cartesian domain using the immersed boundary approach and it shows a very good match with the results. But the same doesn't seem to work with CCS.
I am still figuring out the problem. First of all there is this "1/r" term which I think would lead to discontinuity at the center, r=0. Secondly while setting up the pressure poisson equation I need to add those extra terms that contain "1/r" as the coefficients. There is one little astonishment I get when I remove this term where my solution for velocity field almost matches with the correct solution. But the pressure terms never agree and go on increasing.
If anyone has any idea please suggest it to me.
How are we going to solve a pipe flow problem? especially when it is axisymmetric problem? I think many times you will find that the boundary condition at r=0 is zero gradient, such as dC/rd=0 at r=0 for a mass diffusion problem or such.
Stick with the physics and you might find the answer.
Hi Shiuh, it's a kind of tricky to handle I suppose. But, I am using finite volume method to solve it. Building a 3D flow solver. I am in a mid way and seems like I can get it done. Will reply back as and when I get a confirmation from my code.
Whatever method you used, it's all about the boundary condition, I guess. You can't have a negative radius after all.
Yes you are correct, it's all about the how you apply your boundary condition. And I am still struck at this with FVM. Hope that I will get the code working.
Hi, I just wanted to share my view on the question I posted. I tried out the solutions didn't converge. Cylindrical CS doesn't allow me to calculate in a normal way, though I may have to resort to some specialized approximations. So, the 3d code I tried didn't worked at all, so trying out newer versions. If any one has suggestions, please tell me.
- Badges
- Science topic
- Similar topics
- Engineering
- Thermal Engineering
- Thermofluid
- Fluid Mechanics