4th WCSET-2015 at Japan
Mechanical Engineering:
Title:
Effect of Impeller Diameter on the Flow Characteristics
of a Centrifugal Pump
Authors:
Mohamed Salem, Tarek A. Meakhail, Ibrahim Shafie
Abstract:
Various parameters affect the pump performance. The
impeller outlet diameter, the blade angle, the blade
number and casing are the most critical. In this study,
experimental and numerical investigations are carried
out for two impellers different in diameter with the
same casing. Numerical simulation of the whole machine
(impeller, vaneless diffuser and volute) is performed
using CFX-Tascflow commercial code. A frozen rotor
simulation model is used for the steady state
calculations. The model pump has a design rotation speed
2800 rpm and two impellers with 7 blades (70 mm and 105
mm outer diameters). For each pump, the performance
measurements are measured and CFD analyses are carried
out for different flow rates for steady calculations. It
found from the study that (1) for both pumps, the
pressure developed inside the impeller is not uniform,
and increases gradually from suction to the outlet duct
of the pump. The pressure distribution for small
impeller pump is more uniform in the volute part than
the bigger impeller pump. (2) At high flow rate, for
both pumps, there is no separation predicted in the
plane at midspan, and the separation appears when the
flow rate decreases while a highly massive separation is
predicted at zero flow rates. (3) The back flow
reentering the tongue passage increases with decreasing
the outlet pump flow rate. (4) Large impeller pump gives
more pressure fluctuations at a monitoring point near
the tongue. Finally, a comparison between the CFD and
performance measurement is fairly good.
Keywords: Centrifugal Pump,
Impeller Diameter, Steady, CFD
Pages:
129-137