Research On The Mechanism And Application Of Lobed Nozzle

In engineering application, lobed nozzle is widely used in ejector system. The lobed jet is different from ordinary free jet. A complicated vortex structure exists in the downstream of lobed jet which endows a better performance to lobed nozzle comparing with normal nozzle. Using CFD soft, a systematic numerical simulation has been done according to the universal study scheme which is proposed in this paper. In order to acquire the influence of common structure on ejector performance, the flow field in ejector system is analyzed used total pressure loss and ejector coefficient as index. The following works has been done in this paper:1. Combined with the acquired experimental data in the literature, using the flow field distribution characteristics and the ejector coefficient as index, various turbulence models which can be used in ejector numerical simulation is studied and the appropriate turbulence model is finally determined.2. Base on the structural features of ejector with lobed nozzle, simplified physical models are built and a reasonable gird meshing scheme is determined. A suitable numerical simulation program is selected according to the investigated parameters;3. A full data simulation program is used in this paper to simulation models with different structural parameters. The mechanism of lobed jet is researched according to the analysis of field according in different models.4. The universal structure parameter is selected based on the numerical simulation data and the equation between universal structure parameter and performance parameter of ejector is acquired according to quadratic regression method. The equation is further analyzed according to its response surface.5. The matching scheme of downstream structure of ejector system is studied, when the nozzle structure is determined. The influence of mixing tube parameters on ejector performance is systematic researched.6. A lobed nozzle with hemispherical cavity is first used in ejector system. The study scheme used in normal lobed nozzle is applied in the research of this kind of new nozzle. The commonality of study scheme used in this paper is tested.