The work motivation is determined by the extensive use of interacting swirling flows in counter vortex quenchers and vortex combustion chambers. To optimize the design of such devices, it is necessary to understand the structure of the flow and the mechanisms of interaction of co-axial swirling flows. With regard to burner devices, these studies are important for the most efficient combustion of fuel, reducing the polluting emissions of combustion products and increasing the durability of combustion chambers. The main aim of the study is the experimental investigation of aerodynamic structure of the swirling flow in isothermal model of twostage vortex burner device. The main attention is paid to the mixing process of swirling streams formed in two consecutively connected tangential swirlers representing first and second stages of the burner device. The methods used in the study. Flow visualization for various swirl flow configurations were obtained using a digital high-speed camera. Profiles of the time-averaged axial and tangential velocity components as well as their pulsating parts (root mean square deviation) were obtained using a laser-Doppler anemometer. The results. The formation of a secondary instability of the flow in the form of a precessing vortex was revealed in the case of regime with co-swirl of flows between two stages of the working section. Effective mixing of swirl flows was detected in the counter-swirl mode. Based on the results of conducted isothermal experiments it can be concluded that the counter-swirl mode is more preferable for application in a two-stage burner in terms of the possibility of faster mixing of the burner flows of the first and second stages. The resulting flow is characterized by a more uniform flow distribution inside the device in combination with a stable flow swirling, which should increase the residence time of the fuel particles in the active combustion zone and, accordingly, ensures their complete burn-out. The latter factor is achieved without the development of a strong hydrodynamic instability of the flow, which is characteristic of apparatus with a strong flow swirling.
|Журнал||Известия Томского политехнического университета. Инжиниринг георесурсов|
|Состояние||Опубликовано - 2017|