Centrifugal pump design and analysis
AIM :
Creating a 3D model of a Centrifugal pump, run a baseline flow simulation where inlet flow takes place and then perform a parametric study for different velocities. Showing the Performance diagram and Obtain the relationship between Pressure ratio and mass flow rate and explaining the results.
INTRODUCTION :
1. CENTRIFUGAL PUMP :
Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow. The rotational energy typically comes from an engine or electric motor.
2. MASS FLOW RATE :
The mass flow rate of a system is a measure of the mass of fluid passing a point in the (m) system per unit time. The present study aims to analyze the fluid flow in a flowbench and perform the grid dependency and valve lift test and observe the results.
3. PRESSURE RATIO :
Pressure ratio is the ratio between the outlet pressure and the inlet pressure.
Pressure ratio = Outlet total pressure/ Inlet total pressure
GEOMETRY :
PARAMETERS FOR BASELINE SIMULATION :
PROCEDURE :
Create a 3D Model in Solidworks CAD Software.
Modify the Components in the Components Control.
The Computational Domain is created.
The Rotating Region is selected and the speed is set to 1000 rpm.
The Inlet Boundary Condition is set as Environmental Pressure of 1 bar.
The Outlet Boundary Condition is the Exit Velocity of 15 m/s.
The Surface Goal is set in the Inlet and the Outlet faces.
Then the Mesh is created for the model and the Automatic mesh level is set into 3 and Advanced Chanel refinement is selected.
Run the Simulation and the cut plots are created for the Pressure and Velocity and get the values for the goals.
RESULT - Grid Dependency test
I have set the input variables as output velocity and the values are 10 m/s, 15 m/s, 20 m/s, 25 m/s, 30 m/s. The Level of mesh is set as 3.
The mesh is refined to advanced channel refinement.
OUTPUT & PLOTS :
Inlet pressure remains the same for all the cases but the outlet pressure varies. When the flow rate at the outlet is high the pressure reduces at outlet which results in the decrease in the pressure ratio.
i. Design point 1 at velocity 10m/s :
Velocity Plot
Pressure Trajectory
Velocity Trajectory
ii. Design point 2 at velocity 15m/s
Velocity Plot
Pressure Trajectory
Velocity Trajectory
iii. Design point 3 at velocity 20m/s
Velocity Plot
Pressure Trajectory
Velocity Trajectory
iv. Design point 4 at velocity 25m/s
Velocity Plot
Pressure Plot
Velocity Trajectory
v. Design point 5 at velocity 30m/s
Velocity Plot
Pressure Plot
Velocity Trajectory
GRAPHS :
Pressure Ratio
Pressure Ratio graph
Mass Flow Rate
Mass Flow Rate Graph
Graph of pressure ratio and mass flow rate
CONCLUSION :
It can be observed that with increase in Velocity increases the Pressure Ratio decreases and hence Mass Flow Rate increases with negative sign. i.e. backflowWith increase in Outlet Velocity the Maximum Velocity also increases.With increase in Outlet Velocity the Maximum Pressure decreases.With increase in Outlet Velocity the Average Mass Flow Rate showed a linear variation in the negative direction and hence it increases.