Fluid Mechanics LAB: Dynamic Pumps and Cavitation ENTC - 303 ENTC-303 PROF. ALVARADO

Dynamic Pumps Kinetic or dynamic pumps add energy to the fluid by accelerating it through the action of a rotating impeller. ENTC-303 PROF. ALVARADO

Classification of dynamic pumps Kinetic or dynamic Pumps Radial Flow (Centrifugal) Axial flow (propeller) Mixed flow ENTC-303 PROF. ALVARADO

Performance of Centrifugal Pumps ENTC-303 PROF. ALVARADO

System and Pump Operating Point The operating point of the system is changed by flow control valve ENTC-303

If below vapor pressure, cavitation occurs Cavitation 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 PROF. ALVARADO

Net Positive Suction Head ENTC-370 PROF. ALVARADO

Pump efficiency The overall pump efficiency is a product of the volumetric efficiency and the mechanical efficiency ENTC-303 PROF. ALVARADO

Pump efficiency   (P is in Pa; QA and QT are in m3/s; T is in N-m; N is in Rev Per Second (RPS)) ENTC-303

Overall Efficiency = Vol.Efficiency x Mech.Efficiency Pump efficiency Overall Efficiency = Vol.Efficiency x Mech.Efficiency Actual Power Out = P x QA Actual Power In = Electrical Power Input (Watts) ENTC-303 PROF. ALVARADO

Suction Pressure (psig) Discharge Pressure (psig) 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

Suction Pressure (psig) Discharge Pressure (psig) Trail No. Frequency (Hz) Flow Rate (GPM) Suction Pressure (psig) Discharge Pressure (psig) Pressure Difference (psig) 1 15   2 20 3 25 4 30 5 35 6 40 ENTC-303 PROF. ALVARADO

References Applied Fluid Mechanics, Robert L. Mott www.gewater.com www.pumpworld.com ENTC-303 PROF. ALVARADO