Week 9 - Parametric study on Gate valve.

PARAMTERIC STUDY ON GATE VALVE

AIM :

To perform the Parametric study on gate valve by using ansys fluent

OBJECTIVE :

• To find out the output mass flow rate of the fluid by lifiting the gate discs at different heights
• To clauclate the flow coefficient and flow factor by increasing the gate disc at 10 to 80% height

INTRODUCTION :

The main purpose of the gate valve is to restrict the flowing fluid and also to allow the fluid to pass.In the gate valve we ragulate the flow by using the hand wheel .Mainely the gate valve is used in the pipes and other aplications .the main purpose of this study is to find the mass flow rate at the out put of the pipe ,because the input which we give we won't get at the out put of the pipe due to leakages, minor losses and mainly due to friction .due to these reasons we won't get the accurate results .so inthis study we are going find how much mass flow rate we are getting after lifiting the disc at certain height .

PROCEDURE :

Now we are going to discuss that how we are gonna find the mass flow rate and the solution process .

GEOMETRY:

Now in this i am going to discuss how we import the geometry how i done the solution process and also the caluclation of the mass flow rate and flow factor,flow coefficient

Gate disc lift to 10mm

Gate disc lift to 80mm

• Import the component to the space claim and then select the move option and lift the gaste disc at 10mm and 80m as shown in the figure
• And after that then select the volume extraction option and then extract the volume from the component
• And then supress the components for physics for ,so that they won't cause any error during the solution process
• if the disc won't occupy the lifted volume then click on the volume of the component ,then click on the update on current bodies then we can see that the fluid occupies the fluid volume and then we can exit spaceclaim

MESH:

After mesh generation

Cut section of gate valve

In the mesh we going to use normal coarse mesh and then giving the named section to the component and then update the mesh

SOLUTION PROCESS :

• After the updating the mesh we are going to intialize the sluiton process
• As the gravity acting ,give gravity on Z-axis as -9.81 m/s^2
• The method we are going to use is K-Epslion ,realizable and scalable wall Function
• Add material ,as water -select from the fluent data base and also in Zones change the material asLiquid
• Provide the Boundary conditions -input pressure -12 pa
• Intailize the process ,then select the mass flow rate from the definitions and set the output as the output parameter because we are going to find the mass flow rate of output
• Then run the caluclation and find out the results that we get
• the following below figures shows the process and the results we got

Velocity vector -10mm lift

Velocity plot -10mm lift

Pressure plot-10mm lift

eddy velcoty -10mm lift

80mm lift :

velocity plot -80mm lift

Velocity vector-80mm lift

eddy velocity -80mm lift

Desing points 10-60mm lift

Mass flow rate at 80mm lift

Design point at 80mm lift

• The above contour and plots and the parameter results shows the mass flow rate at different gate disc lifts .As from the design points as the lift of the gate disc increases the mass flow rate also increases.And the another point we sholud consider as the pressure decreases the flow rate as well as the velocity of the flow also increases.now we are gonna caluclate the flow coefficient and flow factor
• The negative sign indicates that the fluid is flowing outwards.

Caluclation and results :

Mass flow rate :

M = rho*Q

m= mass flow rate

rho = density of the fluid

Q = flow rate m3/s

FLOW COEFFICIENT :

Cv = Qsquare root of SP/delta P

Cv= flow coefficient

SG =specific gravity

DeltaP = change in pressure

FLOW FACTOR :

Kv=Qsquare root of SP/delta P

CONCLUSION :

• As from the observation of contour plots and plots results we got ,as the gate disc lift rises the mass flow rate increases
• And same as the flow coefficient and flow factor values also increases asthe gate disc lift rises for certain
• If the valve kept open most of the time then we are going to have the high flow coefficient and flow and also the mass flow rate increases

At finally i can conclude that by doing this challenge i know how to a parametric study in fluent and also how find a mass flow rate of the fluid