# 1)A closed type injector has a nozzle orifice diameter of 0.949mm and the maximum cross sectional ar

1)A closed type injector has a nozzle orifice diameter of 0.949mm and the maximum cross sectional area of the passage between theneedle cone and the seat is 1.75 mm2. The dischargecoefficient of the orifice is 0.85 and for the passage is 0.80. Theinjection pressure is 175 bar and the average pressure of chargeduring injection is 25 bar, when the needle cone is fully liftedup. Calculate the volume rate of flow per second of fuel throughthe injector and the velocity of jet at that instant. Density offuel is 850 kg/m3. 2)A six cylinder diesel engine produces 100 kW at 1500 rpm. Thespecific fuel consumption of the engine is 0.3 kg/kW.h. Eachcylinder has a separate fuel pump, injector and pipe line. At thebeginning of effective plunger stroke of one fuel pump, the fuel inthe pump barrel is 4 cc, fuel inside the injector is 2 cc and fuelin the pipe line is 3 cc. If the average injector pressure is 300bar and average pressure of charge during injection is 40 bar,calculate the displacement volume of one plunger per cycle andpower lost in pumping fuel to the engine (for all cylinders).Specific gravity of fuel is 0.9 and the fuel enters the pump barrelat 1 bar. Coefficient of compressibility of fuel may be taken as 80x 10-6 per bar. 3)Before commencement of the effective stroke, fuel in the pumpbarrel of a diesel fuel injection system is 6 cc. The diameter andthe length of the fuel line from pump to injector is 2.5 mm and 600mm respectively. The fuel in the injection valve is 2 cc. To deliver 0.10 cc of fuel as a pressure of 150 bar, how muchdisplacement the plunger undergoes. Assume a pump inlet pressure of1 bar. What is the effective stroke of the plunger if its diameter is 7mm? Assume coefficient of compressibilityof oil as 75 x 10-6 per bar at atmospheric pressure. . . .