A study of the gas flow through air jet loom

Abstract

Air jet loom,as one of the shuttleless looms,transports a yarn into warps using viscosity and kinetic energy of anair jet.Performance of this picking system depends on the ability of instantaneous inhalation/exhaust,configura-tion of nozzle,operation characteristics of a check valve,etc.In the recent past,many studies have been reportedon the air jet discharged from a nozzle exit,but studies for understanding the flow field characteristics associatedwith shear layer and shock wave/boundary layer interaction in the nozzle were not conducted enough.In this pa-per,a computational study was performed to explain the flow field in the air jet nozzle with an acceleration tubeand validated with previous experimental data available.The results obtained from the computational study showthat,in the supersonic flow regime,the flow field depends significantly on the length of acceleration tube.Asnozzle pressure ratio increases,drag force acting on the string also increases.For a longer acceleration tube,thetotal pressure loss is large,owing to the frictional loss.