Numerical Analysis of the Fiber Fleece Behavior in Roller Drafting in a Transient State
Draft dynamics in a roll draft mechanism have an important influence on the thickness irregularity of the output fiber bundle. This paper is to analyze the dynamics of the roll drafting in time domain based on the governing equations (PDEs system) for bundle flow. Since the governing equations consisting of continuity and motion equations turned out to be a nonlinear problem with coupled variables, the solutions in a transient state could not be obtained by analytical means. We made use of a numerical method. Thus, the total equations system was transformed to an algebraic equations system, which provided us with solutions under given initial and boundary conditions in an iterative fashion. FTCS (Forward-Time Central-Space) difference formula with an explicit Euler scheme as the Finite Difference Method (FDM) turned out to be an effective derivative form for solving our problem. Simulations showed that the response of the output linear density to the disturbance of drafting condition agreed very well with experimental results, and that the transient state of velocity profiles disappeared more quickly than that of the linear density profiles. Based on our model for bundle flow, the existence of draft waves in the linear density fluctuation of the output bundle and a bifurcation in a roll drafting mechanism could be verified.
Bundle flow Governing equation Transient state FTCS Velocity profile Linear density profile Draft wave Bifurcation.
Jong S. Kim Chokri Cherif You Huh
Department of Textile Engineering, Kyunghee University, Yongin, 449-701, Korea Department of Mechanical Engineering, TU-Dresden, Dresden, 01062, Germany Department of Meck, and Ind. Systems Eng. , Kyunghee University, Yongin, 449-701, Korea
国际会议
杭州
英文
43-50
2006-08-22（万方平台首次上网日期，不代表论文的发表时间）