'Pressure relief valve analysis with 6-DoF motion' simulation project by Ali_Arafat


#1

I created a new simulation project called 'Pressure relief valve analysis with 6-DoF motion':

This project simulates opening of a pressure relief valve using 6 DOF body motion.


More of my public projects can be found here.


#2

Description


 

 
High-pressure gas systems are becoming prevalent with the rise in the scale of natural gas transport and its various industrial applications. These high pressures may lead to irregularities in the operation of the pipe system or system failure due to mechanical damage. To prevent this, we use a Pressure Relief Valve. Essentially, a Pressure Relief Valve is a safety valve that enables one to control or curb the pressure in a certain mechanical system. The valve relieves the pressure by releasing the excess, pressurized fluid through an alternative path out of the system, thereby, regulating the pressure of the system. [1]
 
With the help of Computational Fluid Dynamics (CFD), we can simulate a pressure relief valve in the situation of high fluid pressure in the pipeline. The simulation results give us a deep insight into the flow path of the fluid as well as the specific regions of relatively higher pressure. This data is accounted for while making design modifications or choosing the material of various components in a pressure relief valve.
 

Project Goals


 


 
This project simulates the opening of a relief valve by fluid pressure via Transient analysis with six degrees of freedom (DOF) motion for the valve. The valve motion is restrained by adding a spring model that is initially in a slightly compressed state. Turbulence modeling is done with the K-Omega SST model.
 

Geometry


 
The source geometry consists of a complete relief valve, provided by GrabCAD user Johann Oberhumer
The geometry was simplified for this internal flow analysis and is shown in the figure below with the valve highlighted in red.
 


 

Meshes


 
The complete internal flow domain is meshed using the Snappy-Hex-Mesh on the SimScale platform. The resulting mesh (flow domain only ) consists of approximately 0.4 million cells and is shown in the figure below.
 


 

Simulations


 
The fluid is taken as water at standard conditions. A fixed inlet velocity of 8 m/s is taken with a reference pressure of value 0 at the outlet. The restraining spring has a rest length of 0.41 m and a stiffness coefficient of 20000 N/m. Based on the construction and symmetry condition, constraints are applied for the rotations and lateral motions. The job is run on 4 computing cores and takes around 16 hours to complete.
 

Results and Conclusions


 
The simulation analyzes the instantaneous flow field through the valve and the motion due to fluid pressure and spring restraint. The results below (processed on ParaView) show the transient changes in pressure, flow velocities, and the motion of the valve based on the fluid forces. This study indicates potential to improve and optimize the valve design and study the real time valve motion.
 
Also, the figures below show the pressure distribution changes along with a 3D visualization of the streamlines.
 
Shown below is the velocity field at 3 time instances.
 


 

 

 
Shown below is the pressure field at 3 time instances with arrows indicating the flow direction.
 

 

 

 
Shown below is the 3D velocity streamlines in the volume at 3 time instances.
 

 

 

 
Shown below is the plot for displacement of the valve over time.
 

 

 

References

 
[1] https://en.wikipedia.org/wiki/Fundamentals_of_Stack_Gas_Dispersion


#3

Didn't know I could do this, cheers for the example!


Darren