Inlet and outlet of Meridional Velocity on radial impeller design
Inlet and outlet of Meridional Velocity on radial impeller design
(OP)
I have two pump books telling two different story about Cm1 and Cm2. First version said that Cm2 is equal or slightly less than Cm1. Is this statement correct? I highly suspect that this statement is true.
Second book said Cm2=Km(2gh)^0.5, if I use this formula, my Cm2 is much much less than Cm1, which is contradict to the statement of the first book,So which one is correct?
How does one calculate Cm1? Formula Cm1= Volume Flow rate/ Area of eye impeller. Is the area of impeller, which is D1 has to be predetermined before finding Cm1 assumed that shaft diameter is known?
Once you find your inlet angle, let say 20 degree, outlet angle= inlet angle + 9 according to the book. How does one know whether one should add nine, or ten or twelve in order to find the outlet angle. Does this make any different to the performance? Is there any books or graph can be referred saying certain Ns, the inlet and outlet angle should fall between certain value?
These question might sound stupid to some of you, but I really apprecaite someone can explain and answer my question above. Thanks
Second book said Cm2=Km(2gh)^0.5, if I use this formula, my Cm2 is much much less than Cm1, which is contradict to the statement of the first book,So which one is correct?
How does one calculate Cm1? Formula Cm1= Volume Flow rate/ Area of eye impeller. Is the area of impeller, which is D1 has to be predetermined before finding Cm1 assumed that shaft diameter is known?
Once you find your inlet angle, let say 20 degree, outlet angle= inlet angle + 9 according to the book. How does one know whether one should add nine, or ten or twelve in order to find the outlet angle. Does this make any different to the performance? Is there any books or graph can be referred saying certain Ns, the inlet and outlet angle should fall between certain value?
These question might sound stupid to some of you, but I really apprecaite someone can explain and answer my question above. Thanks





RE: Inlet and outlet of Meridional Velocity on radial impeller design
calculated. An example for the 2240 specific speed impeller gives for Z=7, b2=2.0 to 2.4 in., Beta 2=18 to 24 degrees.
RE: Inlet and outlet of Meridional Velocity on radial impeller design
beta 2 does not have to be necessarily larger than beta1?
Would you mind explain how beta 2 depends on number of blazes and b2 ?? it interest me coz I remember reading this somewhere," the BEP and Q can be maintained by increasing b2 where number of vanes and beta2 are reduced." it seems like this 3 features are interrelated like you said.
However, according to the formula, b2=144*Q/(Cm2*PI*D2), here I don't see how b2 can have an effect on Z and beta2 or vice versa. Thanks in advance
RE: Inlet and outlet of Meridional Velocity on radial impeller design