|
[Sponsors] |
How to calculate pressure forces using custom field functions? |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
June 22, 2009, 07:57 |
How to calculate pressure forces using custom field functions?
|
#1 |
New Member
Toni Pujol
Join Date: Jun 2009
Posts: 6
Rep Power: 17 |
Dear all,
I am trying to obtain forces and torques on the blades of an axial fan using a transient simulation. I can obtain them by using the Report => Forces panel. However, I would like to obtain them as a function of time. Therefore, I want to create a Custom Field Function and then make a Monitor => Surface of that Custom Field Function. In order to be confident with what I am doing, I am currently checking if the Custom Field Function I have written gives the same answer as the Report => Forces panel... and I am making one (or several) mistake(s) I am unable to detect. For the x component of the pressure force on the surface, I define a Custom Field Function as: p * x-surface- area and Sum over the surface on the Report => Surface Integrals. The result is very different from that I obtain using the Report => Force panel (it also disagrees with y and z components). Any help? Thanks, Toni |
|
February 9, 2011, 05:10 |
|
#2 |
Member
J.-H. Wang
Join Date: Oct 2010
Posts: 72
Rep Power: 15 |
Hi, Toni.
I ran to the same problem with you. I'm wondering if we misunderstand the definition of "X Face Area" in the droplist of "Mesh" or something else, and neither do I know how Fluent calculate the integrals/sum in the surface monitor operation. This makes me really uncomfortable... If you already find the answer, could you share it some time? It would be helpful, thanks. JH |
|
February 10, 2011, 01:29 |
|
#3 |
Member
J.-H. Wang
Join Date: Oct 2010
Posts: 72
Rep Power: 15 |
Since that no one reponse to this question, I would answer it myself.
First, I need to admit that "X Face Area" is a strange quantity and it seems no one know what it represents. Even the official manual is written in so abstruse language that I doubt that they cannot figure it out either... I have did some experiments on the quantity yet I still coulnd't get it. After spending hours, I quit on this thing. I temporarily use the monitor panel to obtain the force coefficient and it sucks because of the restrictions, anyway if there are people who have better advices I would be much appreciated. JH |
|
April 13, 2011, 03:25 |
|
#4 | |
New Member
qingkai
Join Date: Apr 2011
Posts: 11
Rep Power: 15 |
Hi, JH. Have you solved this problem now?
I have a similar question similar with you, and want to get some advices from you. You know, in Force Report, we can get the force on Wall only. However, I need the force on Wall and another kind of boundary. So I used p*x-surface-area as you ever used before, but the result seems not reasonable. Do you have any idea about my problem? Quote:
|
||
April 13, 2011, 03:34 |
|
#5 |
Member
J.-H. Wang
Join Date: Oct 2010
Posts: 72
Rep Power: 15 |
Actually we are taking different issues: I was stucked on the transient force report, while you are confused about outputting properties of the non-wall boundaries.
What kind of boundaries are you handling here? Try to identify them in the pre-process procedure as an independent wall. That might help. JH |
|
April 13, 2011, 03:36 |
|
#6 |
Member
J.-H. Wang
Join Date: Oct 2010
Posts: 72
Rep Power: 15 |
One more thing, the x-surface-area and the x-face-area is tricky as it seems, you shall examine the mechanisms underlying carefully before utilization. Teach me when you figure it out. :-D
|
|
April 13, 2011, 04:03 |
|
#7 | |
New Member
qingkai
Join Date: Apr 2011
Posts: 11
Rep Power: 15 |
Yeah, I set then as Velocity Inlet because I want to simulate the plasma on the surface. But when it is set as Velocity Inlet, cannot be set as Wall at the same time. I will try to figure out.
Quote:
|
||
June 23, 2017, 15:45 |
How to calculate an equation based on simulated results in post-processing
|
#8 |
Senior Member
Astio Lamar
Join Date: May 2012
Location: Pipe
Posts: 186
Rep Power: 14 |
Hello!
I need to get some values in different places in my domain and do a simple math to calculate. let's assume I have defined Point-A and point-B within the computational domain. then I want to do this: 1-((Velocity@point-A)/(Velocity@point-B)) How can I implement such equation? I tried "Custom Field Function" but there I cannot get velocity or whatever quantity over point or boundaries. Thanks. |
|
Tags |
custom field function, pressure forc |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Moving mesh | Niklas Wikstrom (Wikstrom) | OpenFOAM Running, Solving & CFD | 122 | June 15, 2014 06:20 |
Variable Operating Pressure (field) | Arturo | FLUENT | 0 | April 30, 2008 15:22 |
Execute Command with Custom Field Functions | Prasad Dudhgaonkar | FLUENT | 0 | March 8, 2007 15:27 |
2d foil pressure forces problem | mayor | FLUENT | 4 | December 1, 2003 03:57 |
Using SIMPLE | david | Main CFD Forum | 5 | July 21, 1999 02:38 |