Fluid Mechanics LAB: Dynamic Pumps and Cavitation
description
Transcript of Fluid Mechanics LAB: Dynamic Pumps and Cavitation
ENTC-303 PROF. ALVARADO 1
Fluid Mechanics LAB:Dynamic Pumps and Cavitation
ENTC - 303
ENTC-303 PROF. ALVARADO 2
Dynamic Pumps
Kinetic or dynamic pumps add energy to the fluid by accelerating it through the action of a rotating impeller.
PROF. ALVARADO 3
Classification of dynamic pumps
Kinetic or dynamic Pumps
Radial Flow(Centrifugal)
Axial flow(propeller)
Mixed flow
ENTC-303
PROF. ALVARADO 4
Performance of Centrifugal Pumps
ENTC-303
5
System and Pump Operating Point
The operating point of the system is changed by flow control valve
ENTC-303
PROF. ALVARADO 6
CavitationCavitation is the formation of vapor cavities due to the decrease of the suction pressure to a value below the vapor pressure. If below
vapor pressure, cavitation
occurs
ENTC-303
ENTC-370 PROF. ALVARADO 7
Net Positive Suction Head
vpfsspAvailable hhhhNPSH
Pump efficiency • The overall pump efficiency is a product of
the volumetric efficiency and the mechanical efficiency
PROF. ALVARADO 8ENTC-303
(P is in Pa; QA and QT are in m3/s; T is in N-m; N is in Rev Per Second (RPS))
9
Pump efficiency
%100T
A
ENTC-303
Pump efficiency
ENTC-303 PROF. ALVARADO 10
Overall Efficiency = Vol.Efficiency x Mech.Efficiency
Actual Power Out = P x QA
Actual Power In = Electrical Power Input (Watts)
PROF. ALVARADO 11
Trail No.
Flow Rate (GPM)
Suction Pressure
(psig)
Discharge Pressure
(psig)
Pressure Difference
(psig)
Input Current (Amps)
Input Voltage
(V)
1
2
3
4
5
ENTC-303
PROF. ALVARADO 12
Trail No. Frequency (Hz)
Flow Rate (GPM)
Suction Pressure
(psig)
Discharge Pressure
(psig)
Pressure Difference
(psig)
115
220
325
430
535
640
ENTC-303
PROF. ALVARADO 13
References
• Applied Fluid Mechanics, Robert L. Mott• www.gewater.com• www.pumpworld.com
ENTC-303