Optimization Of Structure Size For Air-jet Loom's Main Nozzle Based On VB

Main nozzle is the core component of the air weft insertion system,the internal structural parameters are directly related to the flow field distribution of the yarn movement,which affects the efficiency of the loom,product quality and production energy consumption.Therefore,it is important to study the relationship between the size of the main nozzle structure and the drag force of the yam.At present,the research on the optimization of the size of the main nozzle structure is limited to a large number of changing structural parameters manually.The numerical simulation combined with the experiment to judge whether the structure is optimal,but the relationship between the optimized variable and the evaluation index is not effectively predicted,and there is no optimization method for forming the structural size parameters of the main nozzle.Therefore,this dissertation takes the main nozzle of ZAX air jet loom as the research object,and takes the internal structural size as the design variable and the drag of the fixed yam at one end as the design goal to study the influence of the internal structure size of the main nozzle on the drag of the yarn.Based on VB software,this dissertation integrates the internal nozzle flow field modeling,flow field simulation calculation,design variable and design target relationship fitting and genetic optimization,which develops an automatic optimization design platform for the main nozzle structure size.Firstly,using the sensitivity analysis method,the variables are subjected to differential operation within a certain constraint interval,and five size variables with large weights on the drag force are sequentially selected.Secondly,the yams of different specifications are selected to set the parameters required by the above optimization software.Through the operation of the optimization software,the function relationship between the dimensional variables and the drag force of the yarn is fitted,and the genetic optimization algorithm is combined,the optimum combination of structural dimensions corresponding to different yarns specifieations and the maximum drag force of the yam are also obtained.Then,through the analysis and comparison of the numerical optimization results,the correctness of the optimization results is verified from the numerical theory,and the following conclusions are drawn:the optimal main nozzle structure size combination corresponding to the yarns of the same type and different specifications is consistent.Finally,the 3D rapid prototyping technology is used to print out the main nozzle model before and after optimization,and corresponding experimental verification is carried out.Through the analysis of the experimental results,it is found that the experimental values of the drag force of the yarn before and after the main nozzle optimization and the simulation results obtained by the optimization of the main nozzle optimization software are better consistency,which verifies the feasibility of the new optimization software platform and the numerical optimization simulation scheme.