Mesures expérimentales et modélisation Analytique de la pénétration d’un jet de Kérosène issu d’un injecteur multi-trous

Abstract

In order to improve the combustion phase in internal engines, it is essential to study the fuel injection process. Indeed, it is during this phase that the performance such as the power developed by the engine or the emissions are determined. It is in this perspective of continuous improvement that the fuel sprays have been studied for many years in the literature. Moreover, the use of diesel injectors results in very different characteristics of fuel spray depending on the geometry of the injector, the fuel used or the conditions of the injections. Along with these influencing factors, the transition to less polluting fuels is also pushing research to continue studying sprays under various conditions. One fuel that could be a good substitute for diesel in diesel engines is kerosene. It is more and more studied and offers characteristics similar to diesel. However, still little work has been done using multi-hole injectors and taking into account the development of the spray when the injection is over. This study aims to model the penetration of a jet of kerosene using a seven-hole injector. The fuel spray penetration is studied during the injection phase, and after the end of the injection, which is rarely the case in the literature. To do this, an experimental set-up is used to capture the fuel sprays using diffuse backlight illumination and the penetration length is measured using an image processing. Subsequently, two numerical models based on articles in the literature are set up and a third is created using non-linear regression on the collected data. All three models use the ambient gas density to predict jet penetration as a function of time. In addition to these two parameters, the first two models also use the momentum flux of the jet while the third uses the difference between injection pressure and back pressure. The first model takes into account instantaneous variations in the momentum flux while the second allows the jet to have a variable density. This makes it possible to predict, at any time, the mass of fuel within the jet as a function of the air-fuel ratio. After the implementation of these models, they are compared with the experimental data and the model taking into account the variable density of the spray offered the most reliable prediction of the fuel spray penetration.

Date	12 Oct 2021
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Patrice Seers (Supervisor)