Prediction of Three-Dimensional Fiber Orientation for Non-Isothermal Flow of Non-Newtonian Fluid

• Main Authors: Wei-cheng Hsieh, 謝瑋晟
• Other Authors: Shiu-wu Chau
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/32989104604412418973

碩士 === 國立臺灣科技大學 === 機械工程系 === 102 === This study is to develop a mathematical model, as well as the corresponding numerical method to simulate steady non-isothermal flow of non-Newtonian fluid along with the fiber orientation distribution in a three-dimensional cavity. The flow modeling with suspending fibers is performed in this study, where the continuity, momentum, and energy equation incorporated with fiber orientation equations are adopted as the governing equations and the modified Cross-WLF model is employed for describing the melt rheology. The governing equations is discretized by a finite volume method and solved in a segregated manner. This study employs a Eulerian approach to simultaneously calculate the flow field characteristics, such as velocity and pressure, and fiber orientation tensor, where all flow and fiber behaviors can be obtained at the same time without requiring any further particle tracing computation. First, this study is validated with a previous study to justify the proposed approach. The approximation scheme, the coefficient of fiber interaction coefficient, the aspect ratio of fiber, the melt material, the inlet temperature and the inlet velocity are adopted to explore the effects of working parameters on the fiber orientation. The results of this study reveal that the melt mainly flows along the longitudinal direction. The predicted orientation tensor component a12, a22, a23 are equal to 0. The coefficient a11 is distributed symmetrical about the x-axis, while the coefficient a13 is asymmetrical about the x-axis. The prediction shows that fiber is perpendicular to the flow direction near the central axis, and parallel to the flow direction near the wall due to shear stress. Inlet velocity has the most significant effect on the fiber orientation.