Gate Valve Parametric Study

A gate valve, also known as a sluice valve, is a valve that opens by lifting a barrier(gate) out of the path of the fluid.Gate valves are used to shut off the flow of liquids rather than for flow regulation. Gate valve require very little space along the pipe axis and hardly restrict the flow of fluid when the gate is fully opened.

Parametric study:-

A parametric study in simulation is done to map the change in inputs to the corresponding outputs. As long as the input parameters and output parameters are connected, the corresponding output values for change in input values are obtained.

In our case the process begines with the creation of an input parameter group in the spaceclaim window. The corresponding parametrized output is the mass flow rate.

SETUP:- The CAD model of gate valve is shown as follows with all the components:-

Sectional view:-

Coponents:-

(1) Bottom:- The fluid volume is formed inside the Bottom on which the analysis is to be performed.

(2) Gate Disc:- Different values of lift (0,10,15,20,25mm) is applied on the Gate Disc.

(3) Spindle and Hand Wheel:- The Hand wheel is used to rotate the spindle there by lifting the Gate Disc.

(4) Bonnet:- The Bonnet is the cover over the bottom.

Extracton of Fluid volume:-

The flow volume contained with in the gate valve is extracted using the volume extract tool. This extracted volume takes into consideration of the void left behind due to the presence of the gate disc.

The pull tool is used to extend the face of the inlet and outlet of the gate valve by 800 mm. The fluid volume is updated in context with the enclosed edges of the gate disc and stem. By doing so,the fluid volume gets adapted to the model with the change in the lift of gate Disc.

Generating the Mesh MOdel:-

The mesh model is generated using the ANSYS meshing module using Body sizing functions. The mathematical mesh model is refined around the flow regions. The generated mesh model is assigned with inlet and outlet boundary conditions. By default, the other surfaces are assigned wall boundary conditions and the volume is given interior conditions.

The Mesh of 5.5 mm size is applied to the geometry of fluid volume which is shown as follows. The variation of lift led to a change in the number of elements by a small amount.

The statistics of the Mesh model are as follows:-

For the analysis, pressure based solver is used. The gravity of 9.81 m/s^2 is applied in negative Z direction. The realizable k-Epsilon turbulance model with scalable wall function is used here for the analysis. The water enters from the inlet at gauge pressure of 10 Pa and leaves at 0 Pa at the outlet. The mass flow rate at the outlet is calculated at Different values of lifts.

Case1:Position of gate valve at 10mm:-

Mass flow rate at the outlet = -0.14853

Section view:-

Contours:-

Case1:Position of gate valve at 15mm:-

Mass flow rate at the outlet = -0.24333

Section view:-

Contours:-

Volume rendering:-

stream lines:-

Animation:-

Case3:Position of gate valve at 20mm:-

Mass flow rate at the outlet = -0.30060

Section view:-

Contours:-

Volume rendering:-

stream lines:-

Animation:-

Case4:Position of gate valve at 25mm:-

Mass flow rate at the outlet = -0.43577

Section view:-

Contours:-

Volume rendering:-

stream lines:-

Animation:-

Case5:Position of gate valve at 30mm:-

Mass flow rate at the outlet = -0.36049

Section view:-

Contours:-

Volume rendering:-

stream lines:-

Animation:-

Observations:-

1. The negative sign in the mass flow rate term comes due to mass leaving the outlet.

2. During each lift, the volume of fluid changes so the number of Elements also tends to change.