@article{oai:kanazawa-u.repo.nii.ac.jp:00010079, author = {Hatta, Kiyoshi and Kinari, Toshiyasu and Shintaku, Sukenori and 八田, 潔 and 喜成, 年泰 and 新宅, 救徳}, issue = {5}, journal = {Journal of Textile Engineering}, month = {Jan}, note = {Various kinds of airflow are used for operating yarn during textile processes. In this study, we calculated numerically compressible airflows past a yarn in a thin pipe in order to operate yarn using both a circular jet and an annular jet. We proposed the way to arrange air drag coefficients of yarns by Reynolds numbers adopted the yarn length exposed to the airflow as the representative length for the higher range of pressured airflows taking their compressibility into consideration. Simulated results elucidated both the air velocity and density profiles in a thin pipe for both jets. In the circular jet, the influence of the potential core was strong but it disappeared comparatively earlier. At higher supplying pressure, the compressed air was not able to fully accelerate in the pipe because it kept high density and took under-expansion. On the other hand, in the annular jet, the influence of the potential core was small, thus the compressed air fully accelerated and expanded in the pipe even at higher supplying pressure. Furthermore, yarn operation experiments showed that increasing supplying pressure was not effective to accelerate yarn running speed, and yarn troubles such as yarn twist or entanglement occurred at supplying pressure higher than 0.3MPa for both jets. © 2006 The Textile Machinery Society of Japan., 金沢大学理工研究域機械工学系}, pages = {217--226}, title = {糸に作用する空気抗力と同軸噴流の糸操作への利用}, volume = {52}, year = {2006} }