@article{oai:kanazawa-u.repo.nii.ac.jp:00009622,
 author = {石田, 稔 and 岡島, 厚},
 issue = {12},
 journal = {繊維機械学会誌 = Journal of the Textile Machinery Society of Japan},
 month = {Jan},
 note = {In this research, the jet-flow characteristics under the tank pressures of 2∼6kgf/cm2 were studied to improve the performance of weft insertion in an air jet loom with a modified reed and auxiliary nozzles. In this case, air-discharge speeds exceed the velocity of sound at higher tank pressures. Furthermore, wefts were actually inserted in the nozzle, and weft traction forces were measured. As the results, the following new facts have been found : (1) The axial changes of the nozzle jet speed and jet diameter below the tank pressure at which choking arises at the exit of the acceleration tube are largely different from those above that tank pressure. (2) The choking arises within the upstream region in the acceleration tube (Mach number=1) and the Mach number at the tube exit exceeds 1. (3) When the Mach number exceeds 1 at the exit of the acceleration tube, expansion waves occurr owing to underexpansion, and the oscillation of compression and expansion waves can be observed in the downstream region. (4) The weft traction force F which represents the weft-flying property in a nozzle increases in proportion to the tank pressure PT, but when the flow is choking at the exit of the acceleration tube, the traction force Fbecomes nearly constant even at higher tank pressures, thus the efficiency of weft insertion becomes reduced . 本研究では, 変形おさ補助ノズル方式AJLのよこ入れ性能を向上させる基礎的研究として, タンク圧PT=2～6kgf/cm2でノズル吐出速度が音速を含む高速ノズル噴流の空気流動特性を明らかにした.さらに, 実際にノズル内によこ糸を入れよこ糸牽引力を測定した.その結果, 以下のことが明らかになった. (1) ノズル噴流速度や噴流径の変化は, 加速管出口で流れがチョークするタンク圧の条件を境にして, 大きく異なる. (2) 加流管でチョークする (マッハ数=1) 位置は, 管出口より上流にあり, 管出口ではマッハ数=1を越える. (3) 加速管出口でマッハ数=1を越える場合は不足膨張のため膨張波が発生し, 下流域に圧縮波と膨張波の振動が生じる. (4) ノズルのよこ糸飛走性を代表する特性値となるよこ糸牽引力Fは, タンク圧PTに比例して増大するが, 加速管出口がチョークするとあまり増加せず, それ以上タンク圧を上昇させてもよこ糸搬送効率が低下するだけである.},
 pages = {T257--T269},
 title = {変形おさ補助ノズル方式エアジェットルームにおける流れ特性: (第2報)メインノズルからの高速噴流とよこ糸牽引力の測定},
 volume = {45},
 year = {1992}
}