Abstract:
In order to fit the actual application of engineering and understand the variations of atomization characteristics of the dual injectors and the single injector, an experimental study on the liquid film breakage length of the liquid-centered coaxial centrifugal pure liquid-phase single-injector and dual-injectors under the same working conditions was carried out in this paper. A high-speed camera was used to capture the transient spray images, and the liquid film breakage lengths of the dual injectors under different working conditions were extracted and analyzed in comparison with those of the single injectors. The surface waves of the liquid film were obtained through image processing to analyze the mechanism of the variations between the liquid film breakage lengths of the single injector and dual injectors. The results show that the liquid film breakage length of the dual injectors is smaller than that of the single injector under the same working condition, and the difference between the liquid film breakage lengths of the single injector and dual injectors show a tendency of increasing and consequently decreasing. The wavelength growth rate defined in the paper reflects the degree of instability of the liquid film before breakage, and the growth rate of the wavelength of the liquid film surface wave of the single injector increases with the increase of the mass flow rate of the liquid, while that of the dual injectors shows that the instability of the liquid film before breakage is not only related to the initial working condition, but also related to the distance between the liquid film impact and the action of the perturbation, so that the wavelength growth rate of the double injectors liquid film surface wave increases first and then decreases with the increase of the mass flow rate.