Research On Characteristics Of Flow Field-yarn Fiber Bundles Based On Fluid-structure Coupling By Nozzles

Air jet loom has the advantages of high speed,high efficiency and wide product adaptability.It mainly adopts the mode of filling insertion combined with main,auxiliary nozzles and a profiled dents.The high-speed jet gathers in the profiled dents to form a synthetic flow field,and the traction yarn completes filling insertion.The synthetic flow field characteristics directly affect the weft insertion quality,weaving efficiency and loom energy consumption.Therefore,it has important theoretical reference and application value in practical application to study the characteristics of the synthetic flow of main and auxiliary nozzles and reeds and the motion state of yarn in the synthetic flow field.In this paper,the weft insertion system of air jet loom is taken as the research object.Through theoretical analysis and numerical simulation,the characteristics of the synthetic flow field in the profiled reed and the fluid-solid coupling between the flow field and the yarn are revealed,and the motion law of the air flow filling insertion in the reed is revealed.The following research progress is made:(1)Using the Reynolds time-averaged equation as the basic control equation to establish the mathematical model of three dimensional flow field of auxiliary nozzle,analyzes the jets characteristics and gas consumption of single round hole,triangle hole and star type hole of a single auxiliary nozzle under the influence of different gas supply pressure,pore diameter.(2)Using Reynolds equation in the standard model synthesis of numerical simulation of multiple auxiliary nozzle flow field,the main nozzle and three auxiliary nozzle jet into the synthesis of the flow field characteristics of profiled dents,this paper discusses the distribution of auxiliary nozzle spacing,gas supply pressure and different pass and auxiliary spray angles research reed passage for synthetic jet flow field characteristics,get the key factors influencing the synthesis center axis velocity of flow field.(3)To establish a mathematical model of the yarn fiber structure with finite element method numerical simulation,the coupling characteristics of two phase flow-yarn discussed different pass auxiliary nozzle on the yarn motion in the synthesis of the flow field,the influence of yarn bending deformation occurred in the flow field,and the yarn is the radial wave law of periodic fluctuation.From the perspective of fluid mechanics,the weft insertion of air-jet loom working process was studied in this paper,based on the analysis of different type of auxiliary nozzle,the synthetic flow field distribution of nozzle and profiled dents and the coupling effect of flow field with weft.Then this research discussed the influence of type and spacing of the auxiliary nozzle,inlet pressure on the flow field characteristic.The research results supply an important theoretical reference value and application value for design of high liability and low gas consumption of weft insertion system.