Question

What is the value of the rate of flow of fuel if the coefficient discharge of fuel is 0.75, area of the jet is 0.885 mm^2, density of the fuel is 780 kg/m^3, and pressure differential causing fuel flow is 15000 Pa?

(a) 3.21 g/s

(b) 4.21 g/s

(c) 5.21 g/s

(d) 6.21 g/s

This question was posed to me in an interview.

This interesting question is from Petrol Engine Fuel System in portion Fuel Supply System of Automobile Engineering

Answer 1

The correct option is (a) 3.21 g/s

To elaborate: Pressure differential causing fuel flow = ΔP = 15000 Pa, coefficient of discharge = Cf = 0.75, density of the fuel = ρ = 780 kg/m^3, and area of the jet = A = 0.885 mm^2. The rate of flow of fuel = Wf = A* Cf*\(\sqrt{2\rho\Delta P}\) = 0.885*0.75*10^-6*\(\sqrt{2*780*15000}\) = 3.21*10^-3 kg/s = 3.21g/s.