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Volume 25, Issue 2
Displaying 1-3 of 3 articles from this issue
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Part 1: Measurements of Air Velocity Distributions in a Model RotorAkira Horikawa, Osamu Yaida, Nobuharu Mimura, Toru Hamada1979 Volume 25 Issue 2 Pages 31-36
Published: 1979
Released on J-STAGE: October 24, 2006
JOURNAL FREE ACCESSTo investigate the air flow in an open-end spinning rotor, the direction and the distribution of the air flow were determined in a model rotor, and the effects of the number of air exhaust holes and the rotor speed on them were considered.
The experimental results were as follows: 1) Nearly equal static pressures were obtained on the same radius in the rotor. 2) The pressure gradient near the air exhaust holes was larger than that of the other parts, and that near the rotor center was flat. 3) The circumferential velocity of the air flow was equal irrespective of the measured plane, the rotor speed, and the number of air exhaust holes. 4) While a forced vortex motion was observed near both the rotor axis and the outer wall, a free vortex motion was observed between these regions. 5) The angle distribution was equal radially irrespective of the measured plane, the rotor speed, and the number of air exhaust holes.View full abstractDownload PDF (579K) -
Masaru Nakajima, Hideo Noshi, Sei Uchiyama1979 Volume 25 Issue 2 Pages 37-43
Published: 1979
Released on J-STAGE: October 24, 2006
JOURNAL FREE ACCESSAn attempt has been made to develop a mathematical model to determine an economically optimal loom speed. The optimal loom speeds have theoretically been analyzed under the following three evaluating criteria; (1) the maximum production rate criterion to maximize the amount of fabrics woven in a unit time or the minimum time criterion to minimize the time necessary for weaving fabrics of unit area, (2) the minimum cost criterion relating to weaving a unit area of fabrics at the least cost, and (3) the maximum profit rate criterion to maximize the profit per unit time. The principle and algorism have been derived to determine the optimal loom speed by using the data obtained in practical weaving mills. Then, an example is shown to prove a simulation model successful.View full abstractDownload PDF (787K) -
Part 2: Analysis of Material Transfer in Fiber Assembly Based on Diffusion TheoryHirohito Matsui, Kazuo Moriyama, Shigenori Fukuoka1979 Volume 25 Issue 2 Pages 44-51
Published: 1979
Released on J-STAGE: October 24, 2006
JOURNAL FREE ACCESSWhen a chemical is washed off from a fiber assembly such as cloth or a yarn, it migrates in the fiber and the water phase in a fiber assembly, and subsequently moves to water.
In such a process the diffusion coefficient of a chemical in a fiber differs largely from that in water. This was analyzed on the basis of a diffusion theory. Assuming that a single fiber is a column and a fiber assembly is a column or a plane board, the following theoretical relations, representing residual ratio of a chemical in a fiber assembly during washing, were obtained: y(t)=∑<∞><i=1>∑<∞><i=1>Aij exp(-Dfμij2/R2t) where t; washing time, sec y(t); residual ratio of a chemical in a fiber assembly Df; ; diffusion coefficient of a chemical in a fiber, cm2/sec R; radius of a fiber, cm Aij; ={2Qi/(1+α)β2μij; 2}2 1/1+α/1+α J1; 2(μij; )/J0; 2(μij; ) …… (column) Aij; =1/2{2Qi/(1+α)β2μij; 2}2 1/1+α/1+α J1; 2(μij; )/J0; 2(μij; ) …… (plane board) Qi; ; root of J0; (Qi; )=0 (column) root of cos(Qi; )=0 (plane board) μij; ; root of Qi; =βμij√1+α 2J1; (μij)/μijJ0; (μij)/μijJ0; (μij) J0; Ji; ; Bessel functions of the 0th and the 1st order α, β: constants depending on the diffusion coefficient of a chemical in a fiber and in water, geometrical characteristics of a fiber assembly and so on.
The values calculated theoretically by using the above equations agree well with experimental values, and are very close to the results obtained by the simplified equation already reported.View full abstractDownload PDF (932K)
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