Calculate the diameter of the injector orifice of a six-cylinder, 4-stroke CI engine using the following data:

Question

Derive an expression for the diameter of the injector orifice to spray fuel Q cm³/cycle/cylinder in terms of injection pressure p_inj(kN/m²), combustion chamber pressure P_cyl(kN/m²), density of fuel r_f (kg/cm³) and period of injection seconds.

         Calculate the diameter of the injector orifice of a six-cylinder, 4-stroke CI engine using the following data:          Brake power = 250 kW,

         Engine speed 1500  r.p.m.

         BSFC =0.3 kg/kW.hr

         Cylinder pressure = 35 bar

         Injection pressure = 200 bar

         Specific gravity of fuel = 0.88

         Coefficient of discharge of the fuel orifice    = 0.92

         Duration of injection = 36° of crank angle.