| The weft insertion of profiled-reed currently becomes the main style. As the basiccomponent of an air-jet loom, the weft insertion process of auxiliary nozzle is directlyrelated to the loom efficiency, product quality and energy consumption and other keyissues. Therefore, research on the process performance of the auxiliary nozzle for an air-jetloom is extremely important. However, the research on flow field of the auxiliary nozzlefor weft insertion is extremely rare, and is rarely reported at present. What’s more, it ismainly confined to theoretical analysis, numerical simulation and laboratory conditions.To study the characteristics of flow field of the auxiliary nozzle for weft insertion, thecombination method of numerical simulation and experimental test has been tookadvantage. A3D model of the flow field of the auxiliary nozzle is established based onPro/Engineer, and the numerical simulation on flow field of the auxiliary nozzle for weftinsertion can be applied by Fluent. Several kinds of auxiliary nozzles are simulated andthen compared with the velocity distribution at the exit of the airflow centerline as theevaluation index. It is verified by the experiment for the numerical simulation. Therefore, itproves that it is feasibility and rationality of the numerical simulation on flow field ofauxiliary nozzle for weft insertion by Fluent.Considering of the importance of the parameters of auxiliary nozzle such as sprayingangle, measurement instrument of dynamic tension instrument and static resistance-straingauge are introduced, the experimental test is completed. The curves of weft tension andair-supply pressure, spraying angle are obtained under the jet-flow of two kinds ofcommon auxiliary nozzles. Meanwhile, the dragging force on weft yarns of jet-flow of auxiliary nozzle is analyzed. Furthermore, the influence of the force exerted on various ofweft yarns under the flow field of auxiliary nozzle for weft insertion are summarized.In order to further understand the weft insertion process of auxiliary nozzle, thesimplified model of combination of flow field with an auxiliary nozzle and a profiled reedis established, and numerical simulation method is used for numerical calculation andanalysis research. It is expatiated that spraying angle of the auxiliary nozzle has influenceon the combination of flow field. From the perspective of fluid mechanics, thephenomenon that the weft yarn is inclined towards the inside of reed groove and keepsflight peaceful can be preliminarily explained.This dissertation deals with the weft insertion process of auxiliary nozzle from theview of fluid dynamics and numerical simulation. The characteristics of flow field ofauxiliary nozzle and dragging force on the weft yarns are revealed. It is expounded that thespraying angle of auxiliary plays an important role on the combination of flow field. Thefilling insertion of flow field of the auxiliary nozzle is analyzed. Some practical productdevelopment and reference conclusions are obtained. The research can provide significantinstructions to further design, manufacture of auxiliary nozzle and energy conservation onan air-jet loom. |
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