|
[Sponsors] |
[GAMBIT] Question about Boundary Conditions with mobile cylinder involved |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
May 29, 2012, 16:43 |
Question about Boundary Conditions with mobile cylinder involved
|
#1 |
New Member
Sam
Join Date: May 2012
Posts: 8
Rep Power: 13 |
I want to solve the following problem, how affects an airfoil the attachment of one cylinder with blades that redirects the airflow toward the airfoil.
First, I'm trying to solve it as a 2D problem but I'm having some problems when I have to put the "Boundary Conditions". How can I impose that the cylinder with blades can move because of the airflow and this affect the airfoil? This is an image of what I'm trying to explain: If anyone can explain me I will be so grateful. |
|
May 29, 2012, 22:39 |
|
#2 | |
Super Moderator
|
Quote:
|
||
May 30, 2012, 00:31 |
|
#3 | |
New Member
Sam
Join Date: May 2012
Posts: 8
Rep Power: 13 |
Quote:
When you say that it cannot be done, do you mean in GAMBIT-FLUENT or in all kind of CFD software? In that case if you can explain me how to implement the two different conditions and I will make some calculations... Is necesary to make a dynamic mesh in order to implement that? |
||
May 30, 2012, 00:43 |
|
#4 |
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41 |
what about sliding mesh with rotor-stator?
you can draw a circle around your impeller, split your domain with this circle. Then you disconnect the disk (with impeller) from domain, assign interfaces on both fluid domains. Then in Fluent set up moving mesh with rigid body motion (rotation) and for sure you can describe rotation from torque with a udf
__________________
In memory of my friend Hervé: CFD engineer & freerider |
|
May 30, 2012, 01:34 |
|
#5 | ||||
Super Moderator
|
Quote:
Quote:
Another important point is that bladed disk center should be placed at origin or otherwise you will have to specify the offset in the solver. So better idea is to put the disk center at origin. Quote:
Quote:
|
|||||
May 30, 2012, 01:48 |
|
#6 |
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41 |
There is a 6DOF udf : pressure force/torque is computed on body and with twice integration you get the displacement/angle for your motion.
__________________
In memory of my friend Hervé: CFD engineer & freerider |
|
May 30, 2012, 14:39 |
|
#7 | |||
New Member
Sam
Join Date: May 2012
Posts: 8
Rep Power: 13 |
Quote:
Quote:
Quote:
Thanks all 2 of you |
||||
May 31, 2012, 00:49 |
|
#8 | ||
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41 |
Quote:
Quote:
I would advice you to test the mdm first with a simple rotor-stator, and with a fixed rpm. Then try the 6dof, and finally introduce your airfoil
__________________
In memory of my friend Hervé: CFD engineer & freerider |
|||
June 25, 2012, 12:47 |
|
#9 | |
New Member
Sam
Join Date: May 2012
Posts: 8
Rep Power: 13 |
Quote:
Please correct me if I have done something wrong 1.Import impeler geometry (face) 2.Domain Geometry(face) 3.Circle around impeler.(face) 4.Split Domain face with circle 5.Substract Circle face with impeller. 6.Mesh 7.BC 8.Define 2 cell zones as fluids I think that I'm doing it correctly but I just wanna be sure, because I don't know if when you said "Then you disconnect the disk (with impeller) from domain" it is well done with my procedure. Thanks |
||
June 26, 2012, 03:11 |
|
#10 |
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41 |
important is that your rotor and stator domain aren't connected.
For that try to move (not copy!) the rotor domain with any vector. If you are able to do it, then both domains are disconnected If not, then copy the rotor domain with any vector, delete the original rotor domain, and move back(not copy) the rotor domain. Take the advantage from this "move" procedure to pick and define the interfaces (else it is more obscur, since they are superposed)
__________________
In memory of my friend Hervé: CFD engineer & freerider |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Boundary Conditions | Thomas P. Abraham | Main CFD Forum | 20 | July 7, 2013 05:05 |
question about boundary conditions | Nick R | CFX | 2 | February 21, 2011 18:58 |
Question about boundary conditions | Damiano | FLUENT | 2 | January 30, 2007 03:59 |
Basic Boundary Conditions Question | vcoralic | OpenFOAM Pre-Processing | 0 | June 26, 2006 07:56 |
[Commercial meshers] Trimmed cell and embedded refinement mesh conversion issues | michele | OpenFOAM Meshing & Mesh Conversion | 2 | July 15, 2005 04:15 |