Week 9 - Parametric study on Gate valve.

Aim:

The aim of the challenge is to perform a parametric study on the gate valve.

Objective:

The main objective of the challenge is to,

• Obtain the mass flow rates at the outlet.
• Calculate the flow coefficient and flow factor for each opening and plot the graph.
• Discuss the results of the mass flow rate and flow coefficient.

Procedure:

1. Importing the geometry in the SpaceClaim.

2. Volume extracting the surfaces.

3. Extending the fluid flow regions.

4. Suppress the solid volume for flow simulation.

5. After completion of geometry creation, enter the mesh for setup the solution.

Case 1:

Gate disk lift = 10

Element size = 5 mm

Case 2:

Case 3:

Flow Coefficient:

The flow coefficient(Cv) of a device is a relative measure of its efficiency at allowing fluid flow. It describes the relationship between the pressure drop across an orifice valve or other assembly and the corresponding flow rate.

`C_v = Q * sqrt((SG)/(Delta P))`

where:

Q is the rate of flow (expressed in US gallons per minute)

SG is the specific gravity of the fluid (SG for water= 1)

ΔP is the pressure drop across the valve (expressed in psi).

The metric equivalent flow factor(Kv) is calculated using metric units,

`K_v = Q * sqrt((SG)/(Delta P))`

Q is the rate of flow (expressed in m^3/h)

SG is the specific gravity of the fluid (SG for water= 1)

∆P is the pressure drop across the valve (expressed in bar).

Kv can be calculated from Cv using the equation:

`K_v = 0.865*C_v`

The below table represents the flow coefficient and flow factor for the different cases.

		All pressures are in pascal
Case	Gate Disk lift (%)	Inlet pressure (p1)	outlet pressure (P)	Differential pressure (∆p)	Mass flow rate Q (kg/s)	Flow coefficient	Flow factor
1	10	10	0.18518371	9.81481629	0.1497323	0.04779411324	0.04134190795
2	20	10	0.48213362	9.51786638	0.24114522	0.07816437434	0.06761218381
3	30	10	1.0772849	8.9227151	0.36148485	0.1210156638	0.1046785492