Motion Wall with Floworks

bilteryst · March 19, 2010, 02:55

Hi,

My problem is quite simple. I'm trying to simulate with CosmosFloWorks an incompressible flow inside a syringe. So the flow just results from the motion of the piston. I just told it seems to be simple and yet, I tried different models without achieving pertinent results. The boundary conditions are a wall motion condition (for the piston) and an outlet static pressure condition.

May I ask some help to achieve a correct CFD model ? Thanks in advance.

Kiat110616 · April 5, 2011, 14:19

Can you post the picture and show the boundary condition was applied in your model?

bilteryst · April 6, 2011, 17:54

We did not continue with this study. But I try the following solutions :
- internal flow, translation speed for the piston, static pressure for the outlet, fixed walls elsewhere (I tried without this last condition too)
- external, but this one is outlandish since we can not use a mix of liquid and gas

We did not succeed in getting results with both previous solutions. So help would be still appreciated

Boris_M · May 22, 2011, 09:07

Hello bilteryst,
it is not possible to simulate moving pistons in FloWorks or Flow Simulation as it is called now. The question is, is it really necessary?
What do you want to find out?
I understand you want to simulate a syringe but if it is just about the flow how it gets into the needle, hence the relatively hard diameter jump then I would say you don't really need a moving piston. You have a diameter of the piston and if you define the pistons motion speed then the diameter*piston speed = volume flow for the inlet.

Regards,
Boris

March 19, 2010, 02:55	Motion Wall with Floworks	#1
bilteryst New Member Join Date: Mar 2010 Posts: 2 Rep Power: 0	Hi, My problem is quite simple. I'm trying to simulate with CosmosFloWorks an incompressible flow inside a syringe. So the flow just results from the motion of the piston. I just told it seems to be simple and yet, I tried different models without achieving pertinent results. The boundary conditions are a wall motion condition (for the piston) and an outlet static pressure condition. May I ask some help to achieve a correct CFD model ? Thanks in advance.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[Commercial meshers] Fluent3DMeshToFoam	simvun	OpenFOAM Meshing & Mesh Conversion	50	January 19, 2020 16:33
Moving mesh	Niklas Wikstrom (Wikstrom)	OpenFOAM Running, Solving & CFD	122	June 15, 2014 07:20
Errors running allwmake in OpenFOAM141dev with WM_COMPILE_OPTION%3ddebug	unoder	OpenFOAM Installation	11	January 30, 2008 21:30
Convergence moving mesh	lr103476	OpenFOAM Running, Solving & CFD	30	November 19, 2007 15:09
Multicomponent fluid	Andrea	CFX	2	October 11, 2004 06:12

April 5, 2011, 14:19		#2
Kiat110616 New Member Kooky Join Date: Mar 2011 Location: Thailand Posts: 20 Rep Power: 15	Can you post the picture and show the boundary condition was applied in your model?

April 6, 2011, 17:54		#3
bilteryst New Member Join Date: Mar 2010 Posts: 2 Rep Power: 0	We did not continue with this study. But I try the following solutions : - internal flow, translation speed for the piston, static pressure for the outlet, fixed walls elsewhere (I tried without this last condition too) - external, but this one is outlandish since we can not use a mix of liquid and gas We did not succeed in getting results with both previous solutions. So help would be still appreciated

May 22, 2011, 09:07		#4
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 24	Hello bilteryst, it is not possible to simulate moving pistons in FloWorks or Flow Simulation as it is called now. The question is, is it really necessary? What do you want to find out? I understand you want to simulate a syringe but if it is just about the flow how it gets into the needle, hence the relatively hard diameter jump then I would say you don't really need a moving piston. You have a diameter of the piston and if you define the pistons motion speed then the diameter*piston speed = volume flow for the inlet. Regards, Boris