Week 9 - Parametric study on Gate valve.

AIM: Parametric Study of Gate Valve.

Introduction: Gate valves are used to regulate the flow as per the requirement. For example, in a pump that is dilevering more mass flow rate than required gate valve will be used at the output to deliver the required mass flow rate of the fluid. In this study we will simulate the effects on the output mass flow rate for differing opening of the valve (10 to 80%).

The process is as follows:

1) Define the fluid of volunme of the incoming geometry. Create parameter for varying length of the valve.

2) Update the fluid volume volume in context.

3) Meshing

4) Setup => Using k-epsillon (Realizable with scalable wall treatment).

4.1) Define boundary conditions

4.2) Create report definition and activte "create Output parameter"

As the gate valve needs to be open for 10 to 80 % the table shows the position in mm.

10%	5.5mm
21%	12mm
40%	22mm
58%	32mm
80%	44mm

Furthetmore, a few properties that need to be defined to understand the efficiency of fluid trnsfer across the pipe.

1) Flow coefficient: It is a metric by which the flow inside the pipe is measured. It is inversly proportional to the pressure drop.

it is given by,

`Cv = Q(S/(trianglep))^0.5`

here,

S = specific gravity of fluid

Q = Mass flow rate

2) Flow Factor: This metric is used all around the world except the US because of their unit system.

It is given by,

`Kv = 0865*Cv`

After running the first test, parameter set are used to further evaluate the value at the ouput.

For the plots of mass flow rate of each case:

The relationship between the flow factor and mass flow rate has been established as shown in the plot.

Discussion of the result:

the study conducted gives substantial information about the efficiency of the gate valve. Few observations that can be made.

a) As the gate openong length increases the mass flow rate increases asn so does the pressure drop. Although, the pressure at the outlet is too small it does hae and impact on the flow coefficient.

The flow factor denotes the effectiveness of the flow and is directly proportional to the mass flow rate.