Study on kerosene atomization process under a high speed air stream

For the needs of fuel-injection system development for the experimental detonation combustion chamber with a rotating detonation (PoiG - Project: "Turbine engine with detonation combustion chamber") a series of experiments with injection of kerosene under a high speed air stream was performed at the Institute of Aviation. The proper preparation of combustible mixture is very important for the initiation and sustenance of a rotating detonation. The task in case of kerosene-air mixture is far more difficult than for mixtures of hydrogen-air or kerosene-oxygen. A simple stream injector has been tested as a base system, and the kerosene was injected perpendicular to the air stream vector directly from the plane wall of the constant cross-section channel. The process of injection and atomization of kerosene was observed in the special transparent visualization chamber, enabling the spray observation of two mutually perpendicular directions. In subsequent experiments air pressure, air temperature and air flow velocity as well as and injection pressure of kerosene were varied. The tested process was photographed and, in case of chosen experiments, filmed using a high-speed digital camera. The surveys were aimed at identifying and assessing of following parameters of fuel atomization process: the range of the fuel stream and filling grade of research channel with aerosol, aerosol homogeneity and the size of forming it droplets, the possible presence of fuel streams flowing down the walls of channel. The resulting photos allowed for more comprehensive, but only a qualitative assess of the spraying process, while the filmed small regions of visualization chamber allowed the counting down and dimensioning of droplets. This paper presents a test facility and measuring techniques applied during the research activity and selected results of carried out tests.