Pump efficiency prediction
Pump efficiency prediction
(OP)
The similarity rules for centrifugal pumps dictate that homologous operating points of a certain pumps (changing velocity) have same efficiency. Starting at BEP of a pump runing, say, 1750 rpm (max. efficiency = 80%), the similarity rules predict that there must be an homologous operating point at lower velocity, say, 1500 rpm with the same max. efficiency = 80%. But practice indicates that at lower velocity the max. efficiency is also lower, then 80% eff. is no possible al 1500 rpm. Theory fails?





RE: Pump efficiency prediction
the similarity laws assume constant efficiency which is clearly incorrect but normally acceptable for small changes in operating variables.
Cheers
Steve
RE: Pump efficiency prediction
Thank you very much for your reply. I found that theory is aprox. OK for flow rates larger and lower than BEP. At BEP same efficiency is inconsistent.
RE: Pump efficiency prediction