The pressure developed by a centrifugal pump for Newtonian liquids that are not highly viscous depends upon the liquid density, the impeller diameter, the rotational speed, and the volumetric flow rate.
(a) Determine a suitable set of dimensionless groups that should be adequate to relate all of these variables.
You want to know what pressure a pump will develop with a liquid having an SG of 1.4 at a flow rate of 300 gpm using an impeller with a diameter of 12 in. driven by a motor running at 1100 rpm. You have a similar test pump in the lab with a 6 in. impeller driven by an 1800 rpm motor. You want to run a test with the lab pump under conditions that will allow you to determine the pressure developed by the larger pump.
(b) Should you use the same liquid in the lab as in the larger pump, or can you use a different liquid? Why?
(c) If you use the same liquid, at what flow rate will the operation of the lab pump simulate that of the larger pump?
(d) If the lab pump develops a pressure of 150 psi at the proper flow rate, what pressure will the field pump develop at 300 gpm?
(e) What pressure will the field pump develop with water at 300 gpm?