Abstract
The paper describes the experimental researches regarding the influence of the pulverisation characteristics by the modification of the injection nozzle holes number upon mediumlarge power direct injection Diesel engine performances.
The modification of the injection nozzle holes number is made while preserving the total injection surface, as in the standard variant, in order not to modify the injection time and the same doses of injected fuel.
The optimum variants, which are to be tested on the engine "at warm" are established by carrying out numerous tests of the modified injection nozzles "at cold". Thus, the costly tests of many injector types on engine are avoided and conclusions may be drawn with regard to the performance of the modified injection nozzles in different working environments. On carrying out the tests, differences were outlined in the jet debiting, as "shorter" or "longer" jets were determined by the position of the injection nozzle needle towards the entry section in the holes.
Keywords: diesel engine, direct injection, injection pressure, smoke degree