Question

Fuel flows in a 3.5-m pipe from a fuel tank to the pump of a jet engine. The flow rate is 200 1/min. At high altitudes the fuel-tank pressure is low,

and there may be considerable danger of the fuel "boiling" or cavitating as it enters the pump. In such a case the pump would be vapor locked and would cease to deliver fuel to the engine. Show qualitatively how the pressure drop in the line varies with its diameter (over a wide range). What would the mini- mum pipe diameter be if a pipe pressure loss of only 3 kPa were tolerable? The pipe has no sharp bends or elbows.