Spring loaded linear motion with PimpleDyMFoam

Carno · April 4, 2018, 04:35

Hi All,

I am trying to simulate a spring loaded valve in OpenaFOAM.
The equilibrium position of the valve or the response of the valve is the outcome of the valve.

The geometry is like this: The valve is seated on the valve seat with the force of the spring. When pressure is applied on the valve in the opposite direction of the spring the valve opens, as the pressure force overcomes the spring force. I want to know the response time of the valve to completely open it.

How to simulate this in openFOAM? This is very typical problem in case of valve simulations. What we need to do in each time step is, to do the force balance (Pressure force (P.A) vs Spring force (preload+k.x)).

If anybody has dynamicMeshDict example for this, it will be great..

Thanks

Carno · August 22, 2018, 10:51

Nobody replied.... I parked the problem that time. Now I have to solve it.

Is it that, I need to edit, solidBodyMotionFunction.H or linearMotion.H for the formula of displacement in a timestep. Please correct me.

A= Area of pressure action
m= Moving mass
k = spring stiffness
L = spring preload

For a time step:
1. Calculate the unbalanced force F = P*A - L
2. Calculate the displacement = s = u*deltaT -0.5*(F/m)deltaT^2
3. Calculate the new unbalanced force = F = P*A - (k*s+L)
and so on.......

My question:
How to calculate the P in the above equation? It is a patctintegrate of wall patch with area A.

alexisq · May 16, 2022, 04:34

Hi Carno,

I'm currently trying to simulate the exact same thing on OpenFOAM.
Did you find a way to do it so you could help me?

Thanks in advance

April 4, 2018, 04:35	Spring loaded linear motion with PimpleDyMFoam	#1
Carno Member carno Join Date: Mar 2009 Posts: 70 Rep Power: 17	Hi All, I am trying to simulate a spring loaded valve in OpenaFOAM. The equilibrium position of the valve or the response of the valve is the outcome of the valve. The geometry is like this: The valve is seated on the valve seat with the force of the spring. When pressure is applied on the valve in the opposite direction of the spring the valve opens, as the pressure force overcomes the spring force. I want to know the response time of the valve to completely open it. How to simulate this in openFOAM? This is very typical problem in case of valve simulations. What we need to do in each time step is, to do the force balance (Pressure force (P.A) vs Spring force (preload+k.x)). If anybody has dynamicMeshDict example for this, it will be great.. Thanks

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August 22, 2018, 10:51		#2
Carno Member carno Join Date: Mar 2009 Posts: 70 Rep Power: 17	Nobody replied.... I parked the problem that time. Now I have to solve it. Is it that, I need to edit, solidBodyMotionFunction.H or linearMotion.H for the formula of displacement in a timestep. Please correct me. A= Area of pressure action m= Moving mass k = spring stiffness L = spring preload For a time step: 1. Calculate the unbalanced force F = PA - L 2. Calculate the displacement = s = udeltaT -0.5(F/m)deltaT^2 3. Calculate the new unbalanced force = F = PA - (ks+L) and so on....... My question:* How to calculate the P in the above equation? It is a patctintegrate of wall patch with area A.

May 16, 2022, 04:34		#3
alexisq New Member Alexis Join Date: Oct 2021 Posts: 7 Rep Power: 4	Hi Carno, I'm currently trying to simulate the exact same thing on OpenFOAM. Did you find a way to do it so you could help me? Thanks in advance