Question

7 and 8. (a) The power P to drive an axial flow pump depends on the following variables: diameter of the rotor, D, density of the fluid, p, angular speed

of the rotor, o, head, H and volumetric flow rate Q. Determine the dimensionless groups for this problem. (b) A model axial flow pump scaled to one-third the size of the prototype has the following characteristics: Power is 3 hp, volumetric flow rate is 4ft/s, head is 12 ft, angular speed of the rotor is 900 rpm and diameter of the rotor is 5 in. If the full size pump is to run at 400 rpm, determine the power required for the pump, the pump head maintained, and the volumetric flow rate Q. Use the dimensionless numbers derived in part (a) (hint: Watch video “Chapter 7-PumpPower.mp4")

Fig: 1