Based On CFD Analysis Of Weft Insertion Flow Of The Main Nozzle In An Air Jet Loom And The Optimization Of Local Structure Parameter

The whole 3-D weft insertion flow of main nozzle of a air-jet loom is stimulated and analyzed by using the CFD (Computational Fluid Dynamics) theory in this dissertation. After the stimulation and analysis of the whole 3-D weft insertion flow of main nozzle of a air-jet loom with different diameter ratio of the yarn guide pipe under four kinds of gas pressure, conclusion has been made that with different diameter ratio of the yarn guide pipe is good for main nozzle's weft insertion flow.This dissertation is consisted of some researches as given bellow:First of all, the research background, function, structure, work process details of the main nozzle in an air-jet loom and the features of flow used in the main nozzle are introduced.Subsequently,on the base of the main nozzle's structure, three-dimensional model is established. According to the work condition of the main nozzle,internal flow field model is built up, then the model is meshed by hypermesh,and the boundary conditions of the grided model are setted up.In the middle of the dissertation, numerical simulation equation and the theory of computational fluid dynamics(CFD) are introduced,which are required during the calculation. Then software Fluent, using instructions and the relevant parameters'setting of fluent are introduced.In the fourth chapter, after the speed,mach number, pressure, density of the numerical stimulated models are analyzed, an optimal results of specific cases is obtained. From the over-all situation, a conclusion is formed that an optimal combination of the gas pressure and the yarn guide pipe's diameter ratio is best.In the fifth chapter, numerical simulation models'best result of this dissertation is compared with former's of the study group. By comparing and analysing speed, mach number, pressure, density, conclusion has been got that main nozzle with different diameter ratio of the yarn guide pipe is better than former's of the study group.In the last chapter, the dissertation's conclution has been made and also this dissertation looks into the future of main nozzle's research direction.