Research On The Dynamic Spray Characteristics Of Swirl Injector

The main clue of this paper is the dynamic characteristics of swirl injector and the dynamic inner flow characteristics and atomization characteristics under different throttling methods have been discussed.The dynamic inner flow charateristics of the standard injector has been researched by numerical simulation.The inner flow characteristics under stable working condition are investigated to analyse the flow process in the injector,and the methods to calculate liquid flim thickness and spray cone angle in outlet are proposed.Under the two types of dynamic working conditions-linear throttling and oscillating condition,the respond of liquid film thickness and spray cone angle in outlet to inlet mass flow rate are researched by means of the analysis of typical working conditions,discovering that there is a phase lag for spray angle and a phase advance for liquid film thickness.A prelimitary explore of phase difference has been conducted to explain these phenomenon.In addition,the dynamic respond characteristics of outlet mass flow rate have been studied.Besides,the study analyses the effect of throttling speed,osillation prequency and relative oscillation amplitude on the respond of inner flow characteristics and mass flow rate to the change of inlet parameters,discovering that the higher the throttlling speed,the more obvious the hysteresis,and the increase of oscillation frequency leads to a more obvious phase lag,too.The experiment method of high-speed photography is applied to study the dynamic atomizaiton of the standard injector.Under linear throttling and oscillating condition,the time-dependent resolution of the spray pattern,spray angle and breakup length and their dynamic respond to mass flow rate are researched,respectively.And the influence of throttling speed,oscillation frequency and the relative oscillation amplitude on these characteristics have been analysed.To specify,the effect and working mechanism of Klystron effect,which happens under oscillation condition,has been studied.