喷气织机新型拉瓦尔辅助喷嘴引纬流场特性研究

An Investigation on Weft Insertion Flow Characteristics of a Novel Laval Relay Nozzle in the Air-jet Loom

中文关键词: 喷气织机  辅助喷嘴  拉瓦尔喷管  数值模拟  气流场

英文关键词: air-jet loom  relay nozzle  Laval nozzle  numerical simulation  air flow field

中文摘要:

      为了提升喷气织机引纬效率，降低能耗，根据拉瓦尔喷管的结构特点对辅助喷嘴进行结构优化设计。通过数值模拟对优化前后的喷嘴气流场特性进行分析，通过监测外流场的压力、速度和质量流率，评估了优化前后喷嘴的喷射性能，并对两种喷嘴在异形筘槽内的合成流场进行轴向和横向速度分布对比。结果表明：优化后的拉瓦尔喷嘴相较于单圆孔喷嘴外流场最大速度提高了 29%，射流核心长度增加了 31.8%，耗气量减少了 32.4%，主、辅喷嘴合成流场交汇最大速度提升 11.2%。拉瓦尔喷嘴在异型筘槽壁面能始终保持较高的气流速度，更利于引纬，相较于优化前的单圆孔结构，拉瓦尔喷嘴结构能量利用率更高，喷射性能更强。

英文摘要:

      To improve the weft insertion efficiency and reduce energy consumption of air-jet looms, the structure of the relay nozzle was optimized based on the structural characteristics of the Laval nozzle. The flow field characteristics of the nozzle before and after optimization were analyzed through numerical simulation. The injection performance of the nozzle before and after optimization was evaluated by monitoring the pressure, velocity and mass flow rate of the external flow field, and the axial and transverse velocity distributions of the combined flow field of the two nozzles in the profiled reed groove were compared. The results show that compared with the single circular hole nozzle, the maximum velocity of the external flow field of the optimized Laval nozzle is increased by 29%, the core length of the jet is increased by 31.8%, the air consumption is reduced by 32.4%, and the maximum velocity at the intersection of the combined flow field of the main and auxiliary nozzles is increased by 11.2%. The Laval nozzle can always maintain a high air velocity on the wall of the profiled reed groove, which is more conducive to weft insertion. Compared with the single circular hole structure before optimization, the Laval nozzle structure has higher energy utilization rate and stronger injection performance.