It is important to improve the performance of sub-nozzles used in air jet looms for energy saving. In this paper, the velocity distribution of jet flow from the present type sub-nozzles are discussed.
At the present investigation four kinds of commercial sub-nozzles with different shapes, such as circular, porous, rectangular and elliptic are employed. It is found that despite of different nozzle shapes the jet velocity distribution from the sub-nozzles shows similar trend to that of the axisymmetric jet from circular tube nozzle. Due to the jet angle is varied by the air pressure supplied, it is necessary to adjust the set-up angle and position of the sub-nozzle according to the air pressure. From the results obtained, it is seen that the performance of the porous sub-nozzle is the best among the nozzles employed.