centrifugal pump analysis
AIM
To create a flow analysis in a centrifugal pump using solidworks flow simulation.
DESCRIPTION ABOUT CENTRIFUGAL PUMP
Centrifugal pumps are a sub-class of dynamic axisymmetric work-absorbing turbomachinery.[1] 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. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber (casing), from which it exits.
Common uses include water, sewage, agriculture, petroleum and petrochemical pumping. Centrifugal pumps are often chosen for their high flow rate capabilities, abrasive solution compatibility, mixing potential, as well as their relatively simple engineering.[2] A centrifugal fan is commonly used to implement a vacuum cleaner. The reverse function of the centrifugal pump is a water turbine converting potential energy of water pressure into mechanical rotational energy.
WORKING PRINCIPLE
centrifugal pump converts rotational energy, often from a motor, to energy in a moving fluid. A portion of the energy goes into kinetic energy of the fluid. Fluid enters axially through eye of the casing, is caught up in the impeller blades, and is whirled tangentially and radially outward until it leaves through all circumferential parts of the impeller into the diffuser part of the casing. The fluid gains both velocity and pressure while passing through the impeller. The doughnut-shaped diffuser, or scroll, section of the casing decelerates the flow and further increases the pressure. It is important to note that the water is not pushed radially outward by centrifugal force (non-existent force), but rather by inertia, the natural tendency of an object to continue in a straight line (tangent to the radius) when traveling around circle. This can be compared to the way a spin-cycle works in a washing machine.
TYPES OF CENTRIFUGAL PUMPS
There are several types of centrifugal pumps that are useful for transferring fuel and other types of liquid, including radial and axial centrifugal pumps.
Radial centrifugal pumps facilitate a flow that is sped up in an outward motion via a pump impeller. The energy is transferred to a chamber, which then allows the fuel to exit the pump into downstream piping.
These types of centrifugal pumps are also differentiated via their vertical and horizontal shaft orientation, and they offer different applications and restrictions. For example, a horizontal centrifugal pump is easy to maintain thanks to easily accessible internal mechanisms, while a vertical centrifugal pump’s maintenance can be more challenging.
On the other hand, axial centrifugal pumps produce flow from the impeller vane’s propelling or lifting effect.
DIAGRAM OF CENTRIFUGAL PUMP
CENTRIFUGAL PUMP DIMENSIONS
- Diameter of the volute casing is 90mm
- Thickness of the volute casing is 20mm
- Diameter of the inlet suction cylinder is 30mm
- Diameter of the delivery pipe is 12mm
BOUNDARY CONDITIONS
- Make the necessary geometry as mentioned above in the dimensions segment.
- Now create a new project in new wizard tool
- Create lids at the inlet and exit of the pipe
- Now give the necessary boundary conditions
- Inlet pressure is environmental pressure and outlet is velocity.
- The rotor is covered all over by the sides.
- Now give the rotational speed of 1000 rad/sec
- By doing these,the simulation will run smoothly.
RESULTS OF SIMULATION
RESULTS SHOWING THE VALUES FOR PRESSURE AT INLET AND OUTLET WITH MASS FLOW RATE.
PUMP GEOMETRY DIAGRAM
IMAGE OF VELOCITY
PERFORMANCE CURVE PLOT
IMAGE SHOWING PLOTS FOR MASS FLOW RATE AND PRESSURE RATIO.
PRESSURE RATIO PLOT
TRAJECTORY IMAGE
SWIRL MOVEMENT
RESULTS
The mass flow rate increases with increase in velocity atv constant speed.Negative mass flow rate indicates the flow is aginst the casing.By increasing the number of iterations we can see the pressure increases.
REFERENCE