Practical Research of the Angle of Thermodynamic Losses when Indicating Pressure in the Cylinder Diesel Engine

 

Željko Bulatović

Dragan Knežević

Miodrag Milić

 

Very important literary source for the study of work processes in the engine cylinders, for decades, has been an article by Günter Hohenberg "Definition und Eigenschaften des termodinamischen Verlust-winkels von Kolbenmaschinen", published in 1976 in the magazine Automobil Industrie, Edition 4. This article theoretically and practically (experimentally) deals with the topic of determining the angle of thermodynamic losses on the pressure curve without combustion measured in the engine cylinder. The special value of this research is in the experimental results obtained by averaging the measured data on a large number of different engines. It has been shown that these experimental results are useful for a quick, but quite accurate, determining of the angle of thermodynamic losses on the pressure curve without combustion, with any engine. Diagrams proposed by Hohenberg are used today, whether they are applied directly or used for comparison with the results of some of the more modern computational methods based on thermodynamic analysis of the processes in the engine cylinder. However, the theoretical approach by Hohenberg to the given problem through the equations he set, gives a pretty good idea of the most influential factors on the size of the angle of thermodynamic losses, but it has a lot of mistakes and rough approximations. This work is dedicated to the good and bad sides of this very important literature source through a comparison with one of the modern thermodynamic methods related to the issue of determining the angle of thermodynamic losses

Key words: IC engine, diesel engine, engine cylinder, compression ratio, pressure measurement, thermodynamic losses.