Experimental investigation on air-jet loom sub-nozzles for weft yarn insertion

The analysis of the airflow from sub-nozzles having different emitting cross-section is described. At first, tests were carried out outside the profiled reed and comparison between nozzles was made in terms of air velocity distribution, jet spreading, consumption and exerted drag force. Subsequently, in order to analyse the interaction between the jet emitted by a sub-nozzle and the loom profiled reed, some velocity measurements were repeated inside the weft passage, at various distances from the nozzle exit. Finally, a high-speed camera was used to visualize the weft yarn crossing the weft passage.