Week 9 - Parametric study on Gate valve.
Aim:To Perform a parametric study on the gate valve simulation by setting the opening from 10% to 80%
Objective
- To obtain the mass flow rates at the outlet for each design point
- To Caluclate the flow coeffecient and flow factor for esch opening and plot the graph
- To Discuss the results of the mass flow rate and flow co effecient
Theory
A gate valve is generally used to completely shut off fluid flow or, in the fully open position, provide full flow in a pipeline.If the gate valve is partially opened,it may suffer from vibration in which the valve may move from its assigned position Thus it is used either in the fully closed or fully open positions. A gate valve consists of a valve body, seat and disc, a spindle, gland, and a wheel for operating the valve. The seat and the gate together perform the function of shutting off the flow of fluid.When the gate valve is fully open, there is no obstruction in the flow path and it has very low pressure drop. If the fluid is very viscous a special type of gate valve known as a knife gate valve can be used.
Geometry
- Import the CAD model to the space claim for clean up the geometry
- Exract the fluid volume from the geometry
- lift up the gate disc about 10mm
- Extend the fluid flow region about 800mm
Meshing
- Naming the Boundary condetion as Inlet,Outlet , and wall boundary condetion
- Generate the mesh acoording to the Grid size.
Case Setup
- Steady state , Pressure based solver is used
- Enabled the gavity option , 9.81kg/ms^2 in y -axis
- k-epsilon, realizable , scalable wall function viscous model is used
- Pressure inlet, velocity outlet, no slip wall boundary condetion is used
- inetialize the solution
Results
Casee-1 -20% opening
Case-2- 30% Opening
Case-3-40% Opening
Mass Flow Rate Table
| S.I | % Opening | Mass flow rate(kg/s-1) | Pressure Drop | Kv | Cv |
| 1 | 10 | 0.14 | 9.81 | 54.58 | 63.09 |
| 2 | 20 | 0.23 | 9.38 | 88.45 | 102.25 |
| 3 | 30 | 0.35 | 8.59 | 138.73 | 160.38 |
| 4 | 40 | 0.46 | 7.57 | 189.73 | 219.33 |
| 5 | 50 | 0.55 | 6.55 | 236.74 | 273.67 |
| 6 | 60 | 0.62 | 5.62 | 286.51 | 331.21 |
| 7 | 70 | 0.68 | 4.80 | 338.63 | 391.46 |
| 8 | 80 | 0.78 | 4.02 | 395.47 | 457.16 |
Reslults & Conclusion
- Mass flow rate and velocity rate increases with incresing the percentage opening
- Gate valve should work either fully closed or fully opened because the partially opened gate valve might get damaged because of vibration
- Flow coeffecient and flow factor increases with increase in the opening percentage.