Open Access Dissertation
The purpose of this study was to investigate the possibility of reducing diesel engine torque variation by optimizing fuel injection nozzle tip configuration. In order to reduce engine torque variation, test runs were conducted to determine whether fuel injection nozzles affected diesel engine torque. There was a further effort to determine whether a correlation existed between the fuel injection nozzle roto flow and hydra flow, and the engine torque at specified engine speeds.
Engines installed in cotton pickers and tractors were used for this study. Engines, five from the cotton picker and five from the tractor group were chosen randomly from those which were produced by the same group of people under the same production conditions. These restrictions minimized variation associated with nozzles and pumps. These engines were then put into the screen tests to make sure they were quality engines.
The experiments with the selected engines were conducted in the manufacturer's test cell and data were gathered at seven different engine speeds.Three levels (higher limit, medium, and lower limit) of nozzle roto flow and hydra flow were employed in the diesel engine injection system during the experiment. The investigation consisted of two limited-time production style tests. One test was without restrictions and the other was with restrictions. Fifteen calibrations for the tractor engine group and 15 for the cotton picker engine group were recorded for the nozzle roto flow and hydra flow, and the corresponding engine torque.
Two-way ANOVA and correlation statistical procedure were used to analyze the data derived from the experimental sequences. These statistical procedures were used for the following purposes:
1. Investigate the effect of different levels of nozzle roto flow and hydra flow on engine torque.
2. Identify the difference between the effect of nozzle roto flow and hydra flow on engine torque and that of chance variables.
3. Determine the Pearson's correlation coefficient r between nozzle roto flow and hydra flow and engine torque at each engine speed.
4. Determine linear relation between nozzle roto flow and hydra flow and engine torque at each specified engine speed.
The statistical analyses indicated that different levels of fuel injection nozzle roto flow and hydra flow significantly affected diesel engine torque. The data also revealed that the effect of nozzle roto flow and .hydra flow on torque was independent of engine speed. The collected test data from the nozzle roto flow and hydra flow study further confirmed that engine speed affected engine torque. There was a significant positive correlation which was greater than 0.94 at each tested engine speed between nozzle roto flow and hydra flow and diesel engine torque. Linear relations between nozzle roto flow and hydra flow and the engine torque at each specified engine speed were determined.
For cotton picker and tractor engines, a precise prediction of engine torque from a specific fuel injection nozzle roto flow or hydra flow can be calculated directly from the equations developed in this study. The findings could also help engine manufacturers more effectively choose the optimum fuel injection nozzle roto flow or hydra flow for the nominal torque required of the engine. This will better control engine torque variation.
Year of Submission
Doctor of Technology
Department of Industrial Technology
John T. Fecik, Advisor
1 PDF file (xi, 156 pages)
©1995 Guang Jin
Jin, Guang, "Investigation of the relationship between fuel injection nozzle roto flow and hydra flow and the engine torque of a diesel engine" (1995). Theses and Dissertations @ UNI. 794.