Fuel Injector 107-1230 1071230 for Caterpillar 950f 950f II 960f Caterpillar 3114 Engine Caterpillar 3116 Engine

The effect of nozzle diameter, injection pressure and ambient temperature on spray characteristics in diesel engine (part 4)

As the graph illustrate the penetration length at Figure 9 and Figure 10 using different ambient

temperature for 0.12 mm and 0.2 mm nozzle diameter constantly increase with the time taken and both for temperature the penetration length not give much different. This is due to the range of between temperatures not too big. However, the injection pressure influences the spray penetration length, where variant injection pressure which is 40 MPa, 70 MPa and 140 MPa with ambient pressure 1 MPa at atmospheric pressure. As the higher pressure injector, the longer length penetration will influence. This is because the spray was resisted with the ambient pressure.

Figure 11 and 12 show the graphs of breakup length with 0.12 mm and 0.2 mm nozzle diameter. There is fluctuation result on the temperature 500 K, where injection pressure 140 MPa and nozzle diameter 0.2 mm dramatically increase from the 1 mm stood up to the 2.3 mm. This is maybe due to the droplet did not breakup and its getting longer, this is call as the section of ligament. Compare to the temperature 700 K at the 140 MPa and 0.2 mm breakup length flows steady with the time. Thus the temperature influences to the higher ambient temperature used, the shorter breakup length happen at the core segment.

4. Conclusion

This study has shown a simulation flow of the fuel flowing in the nozzle spray before combustion. A low injection pressures in the chamber will disturb the breakdown of the fuel spray to a very fine droplets before start ignition of the fuel. A temperature change in the chamber also affects the length of the spray penetration. For high ambient temperatures, fuel evaporates more easily and ignites the fuel itself. Also, the diameter of the nozzle also affects the breakup length of the spray nozzle as influenced by the higher injection pressure where the breakup length is getting shorter