PumpsPumpsPresented by: Group LPresented by: Group LMaema
GPMaema GPManqele NAManqele NAMokoena SFMokoena SF
IntroductionIntroduction AimsAimso Investigate the HQ curves of
pumpsInvestigate the HQ curves of pumpso Determine the accuracy of
the affinity Determine the accuracy of the affinity lawslawso
Correlate the results withCorrelate the results with theorytheory
TheoryTheory Momentum balanceMomentum balancesW F z gP u 22= +
++Pressure drop across the pumpPressure drop across the pump
The pressure head can be obtained asThe pressure head can be
obtained as z g g h Pwater water Hg = !gWhs= Anity la!s "
correlationAnity la!s " correlationo"elating flow and the pump
speed "elating flow and the pump speedo"elating the head and pump
speed "elating the head and pump speedoCorrelation Correlation2#2#$
=QQ r Q22#2#2 2= HHr Hb aQ H + = StroboscopeStroboscopeo %easure
speed of fast moving ob&ects%easure speed of fast moving
ob&ectso Images on the coupling device'Images on the coupling
device'o( stroboscope speed of ) rpm( stroboscope speed of ) rpm* )
) 2 ) ApparatusApparatus #esults #esults ""$iscussion$iscussion
#otameter calibration cur%e#otameter calibration cur%e &'(
characteristic cur%e&'( characteristic cur%e Anity la!s !ith
respect to ))*+, rpmAnity la!s !ith respect to ))*+, rpm Anity la!s
!ith respect to -.-/ rpmAnity la!s !ith respect to -.-/ rpm
0orrelation0orrelation Sum o1 squared errors 1or Sum o1 squared
errors 1or cur%e 2ttin3cur%e 2ttin3oThe sum of the s+uared errors
for the The sum of the s+uared errors for the lowest speed!,,-./
rpm is lowest speed!,,-./ rpm is 2.0-12-342.0-12-3401 01 oThe sum
of the s+uared errors for the The sum of the s+uared errors for the
highest pump speed is highest pump speed is 0.22$5220-5 0.22$5220-5
0onclusion0onclusion The correlation gives a good precision at The
correlation gives a good precision at low low flow rates.flow
rates. The affinity laws give the best precision at The affinity
laws give the best precision at all flow ratesall flow
rates6riction plays a significant role in the head 6riction plays a
significant role in the head of the pump at very high flow rates.of
the pump at very high flow rates.The endThe end
(uestions(uestions444444
