Performing a parametric study of Gate valve simulation using ANSYS FLUENT

OBJECTIVE:

• To perform a parametric study on the gate valve simulation by setting 5 design points starting from the initial condition of lift with the least value of mass flow rate.
• Postprocess the velocity contour.

Gate valve:

• It is defined as the type of valve which uses gate or wedge shaped disk and the disk moves perpendicular to flow to start or stop the fluid flow in piping rather than flow regulation unless it is specifically designed.
• When the gate valve is fully open, the disk of a gate valve is completely removed from the flow.Therefore no resistance to the flow.Due this very little pressure drops when fluid is flowing through gate valve.
• It has wide application in many areas but very often used in petroleum industries,fire water services.
• Advantages: easy to install,fluid resistance of valve is less,It has dual flow direction.It\'s not subjected to flow direction for a medium.Therefore it is used for pipeline where the medium change the flow direction.
• Disadvantages: It cannot be used to control the flow.when the valve is partially open , it creates vibration and noise.

METHODOLOGY:

1.Geometry-Spaceclaim:

fig.Gate valve

fig.Gate valve geometry assemblies.

fig.Gate valve geometry with pipe

• Lift the component by 10 mm and enable the P(parametric group is created) using Move option.
• Extracted the fluid volume using volume extract option.
• Enable the suppress for physics of all components except the fluid volume.
• Created a pipe with length of 800 mm from the inlet and outlet face using Pull tool option.

2.Mesh:

fig.Mesh with 20 mm element size

• Default tetrahedral mesh is created with mesh element size as 20 mm for all design points.
• Naming the selection such as inlet and outlet.

fig.Mesh metric graph (element quality)

3.Setup:

• Solver : steady,pressure based,absolute velocity formulation,gravity z=-9.81 m/s-2
• Viscous:k-epsilon--->realizable--->Scalable wall function.
• Material: Fluid - Water-liquid.
• Boundary condition: Pressure inlet --> 10 pa(Total guage pressure),pressure outlet- 0 pa.
• Created a mass flow rate report at outlet using Definition option.
• Created a velocity contour.
• Standard initialization is done.
• Run the calculation for 250 iterations.

4.Solution:

1. Design point 1 (10 mm Lift):

fig.Fluid volume adapted for 10 mm lift.(YZ PLANE)

fig.velocity contour for 10 mm lift.(YZ PLANE)

2.Design point 2 (15 mm Lift):

fig.Fluid volume adapted for 15 mm lift.(YZ PLANE)

fig.Velocity contour for 15 mm lift.(YZ PLANE)

3. Design point 3 (20 mm Lift):

fig.Fluid volume adapted for 20 mm lift.(YZ PLANE)

fig.Velocity contour for 20mm lift.(YZ PLANE)

4. Design point 4 (25 mm Lift):

fig.Fluid volume adapted for 25mm lift.(YZ PLANE)

fig.velocity contour for 25mm lift.(YZ PLANE)

5. Design point 5 (30 mm Lift):

fig.Fluid volume adapted for 30mm lift (YZ PLANE)

fig.Velocity contour for 30mm lift (YZ PLANE)

RESULTS AND DISCUSSIONS:

1)

• As we see from the table, mass flow rate at an outlet increases as we increasing the gate lifting length.
• Negative sign in mass flow rate value indicates that the fluid is moving out of the volume.

2)

fig.velocity contour for 30 mm lift (YZ Plane).

For all the five design points maximum velocity is seen at the fillet region which is in red colour this is because low pressure region is created at this region.It is also observed that the velocity values are slightly increasing with lift length.

CONCLUSION:

Performed a gate valve simulation and mass flow rate is obtained for five different points.

Link : https://drive.google.com/open?id=1tyChBJ9oJxMKryyXv_ul69YS89P11-9X