|
[Sponsors] |
Pressure from Particle Image Velocimetry Measurements |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
November 28, 2022, 09:37 |
Pressure from Particle Image Velocimetry Measurements
|
#1 |
Member
E
Join Date: Mar 2018
Posts: 77
Rep Power: 8 |
Hello to everyone,
I got the instantaneous 2D velocity measurements from Particle Image Velocimetry inside the region of a hydraulic jump. I want to calculate the mean time pressure field from the mean time velocity measurements by the numerical solution of the Reynolds averaged Poisson Pressure equation. I solve the resulting system with the Jacobi method but the iterative algorithm does not converge as the absolute difference between the updated pressure field and the pressure field calculated from the previous iteration is not getting smaller. Any ideas for the problem ? Thank you. |
|
November 28, 2022, 17:20 |
|
#2 | |
Senior Member
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 6,776
Rep Power: 71 |
Quote:
Could you give the details? I suppose you want to solve Div Grad p = source, the LHS being in your case? But to state the full Poisson problem you need to prescribe the BCs, how did you prescribe that? Are you working on a cartesian structured grid? |
||
November 29, 2022, 05:00 |
|
#3 | |
Member
E
Join Date: Mar 2018
Posts: 77
Rep Power: 8 |
Quote:
Yes I want to solve Div Grad p=source. The equation follows the Reynolds average approach, so Poisson equation for pressure also contains the Reynolds shear stress terms in the RHS. All BCs are Newmman conditions regarding the grad(p) calculated from the two dimensional Reynolds averaged Navier Stokes equations. I work on a cartesian structured grid which is the same with the grid that the velocity has been measured with PIV. |
||
November 29, 2022, 05:06 |
|
#4 | |
Senior Member
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 6,776
Rep Power: 71 |
Quote:
Tu ensure convergence of an iterative method, you have to fulfill the compatibility condition. Thus, I suppose you prescribed the Neumann conditions in a non correct way. Check for similar discussions in this forum. |
||
November 30, 2022, 06:43 |
|
#5 | |
Member
E
Join Date: Mar 2018
Posts: 77
Rep Power: 8 |
Quote:
Thank you. |
||
November 30, 2022, 08:43 |
|
#6 | |
Senior Member
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 6,776
Rep Power: 71 |
Quote:
That is a classic topic in mathematical anaysis of PDE. Just search on Google: https://www.google.com/search?client...eumann+problem |
||
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
viscosity udf don't use correct temperature and strain rate | rezvani | Fluent UDF and Scheme Programming | 8 | May 27, 2021 05:40 |
Getting divergence while increasing the back pressure at pressure outlet | greenfields15 | FLUENT | 0 | March 18, 2018 23:39 |
Periodic flow using Cyclic - comparison with Fluent | nusivares | OpenFOAM Running, Solving & CFD | 30 | December 12, 2017 05:35 |
Particle tracking error | alchem | OpenFOAM Bugs | 5 | May 6, 2017 16:30 |
Hydrostatic pressure in 2-phase flow modeling (long) | DS & HB | Main CFD Forum | 0 | January 8, 2000 15:00 |