Question # 1 (35 Pts.) a) (s For laminar flow in circul lar tube, the friction f
ID: 2088598 • Letter: Q
Question
Question # 1 (35 Pts.) a) (s For laminar flow in circul lar tube, the friction factor depends upon the tube rou factor (k)- true or false. Give reasons for your choice. Your friend makes a statement that since the axial pump provides very low discharge, it can be used both for residential and commercial purposes-is this statement true or false? Give reasons for your choice ghness b) a) e) The velocity of water in a square duct (0.4 m sides) is 0.5 m/sec. The flow in the d full. Is this flow laminar, turbulent, uniform or non-uniform? uct is d) (s) Explain the term NPSH and state its significance. e) s) What is the difference between pumps operating in series and in parallel arrangement? f) (s) Explain the significance of the velocity correction factor a 8) (s) Explain the significance of the Pump Characteristics curves.Explanation / Answer
a) False, the friction factor is independent on roughness factor in laminar flow. This is because all the disturbamces caused by this roughness is quickly damped by viscosity.
b) True, they can be used for both commercial and residential purposes. They can be used to circulate fluids in powerplants, sewage plants, evaporators etc and also used for irrigation systems. This is because they hve high flow rates and also low pressures.
c) The term NPSH is Net Positive Suction Head and it is of two types :
available NPSH (NPSHA) and required NPSH (NPSHR).
NPSHA shows the absolute pressure at suction port of ump and NPSHR shows the minimum pressure that is required at the suction port. This keps the pump from cavitating and hence this minimum pressure needs to be there always.