Method of Estimating the Quality of the Process of Creating the Fuel-Air Mixture in a High-Speed Diesel Engine

One of the basic problems of improving the transport diesel parameters (the fuel economy and decreasing the exhaust gases pollution) is the perfection processes of fuel dispersion and fuel-air mixture creation. The difficulty of estimating the quality of these processes is caused by the complexity of the process in the diesel combustion chamber when the fuel is injected and evaporated. This paper offers a new method of estimating the quality of creating the fuel-air mixture in a high-speed diesel engine. The method is based on the results of non-motor tests. According this method, in a customary stand, used for test the diesel engines fuel-delivery equipment, an extra sensor is added to record the force of hydro-dynamic pressure of a fuel jet on a sensitive surface of the sensor. This sensor is created on the basis of a piezoelectric element, which has high sensitivity and good frequency characteristics (measuring range of frequencies up to 90 kHz). On the sensitive surface of the sensor, the small plate with 0.2 g weight and 18 mm diameter was glued. During the tests on the stand, it was possible to change the distance between one of the injector's nozzle hole and the sensitive surface of the sensor. The sensor was installed in two positions: at distance of 5mm and 50 mm from the nozzle hole of the injector. The analysis of a number of parameters (the value of the force of hydro-dynamic pressure of sprayed fuel jet, the speed of jet spread, etc.), has allowed to estimate quality processes fuel / air mix creation for different types of sprayers.