Development of High Efficiency and Quality Interlacing Process by High Speed Air Flow Simulation

本研究旨在通过数值模拟对高效、高质量的交联过程进行优化。得到的结果如下：(1)采用TVD格式和将圆柱体视为单丝在交织器中的计算模型，计算了高速均匀气流撞击圆柱体时圆柱体周围的气流（流速、压力、密度、阻力等）。气缸周围的激波分布强烈地依赖于远离气缸的气流速度。阻力系数随气流速度增大而增大。压力阻力系数远大于摩擦阻力系数。(2)采用平行板间放置薄圆柱的计算模型，采用TVD格式进行了数值模拟。在特征马赫数大于1的情况下，薄圆柱的阻力系数几乎与特征马赫数无关。因此，提高纱线的流速对纱线的运动是无效的。并且存在一定的最佳交错器几何形状，以便进行有用的交错处理。(3)实验测量了纱线管道中静滚筒的阻力。射流边界上阻力时间平均梯度变大，射流边界与对壁面相交处阻力随时间变化较大。在这两个地方，细丝的相对位置会有很大的变化。因此，可以进行有用的交错处理。(4)如上所述，我们获得了高质量、高效率的交错工艺指南。(1)空气流速存在一定的最优值。多余的气流速度不利于有效的交错处理。（ii）对交织过程有贡献的细丝的阻力在很大程度上取决于交织器的几何形状。

This study has been carried out for the purpose of the optimization of the interlacing process having high efficiency and quality by numerical simulations. Results obtained are follows :(1) By the use of TVD scheme and the calculation model that a cylinder is treated as a mono filament in interlacer, we calculated the air flow (flow velocity, pressure, density, drag, etc.) around a cylinder in case that high speed uniform flow of air strikes the cylinder. The shock wave distribution around the cylinder depended strongly on the air flow velocity far from the cylinder. The drag coefficient increased with the air flow velocity. And the pressure drag coefficient was much larger than the frictional drag coefficient.(2) The numerical simulation using TVD scheme was carried out by the use of the calculation model that a thin cylinder is placed between parallel plates. In the case of the characteristic Mach number more than unity, the drag coefficient of the thin cylinder was almost independent of the characteristic Mach number. Therefore, to increase flow velocity is not effective in the motion of a yarn. And there is a certain optimum geometry of an interlacer for useful interlacing process.(3) We measured experimentally the drag of a static cylinder in a yarn duct. The gradient of time average of drag became large on the air jet boundary, and the drag varied widely from hour to hour on intersection between the air jet boundary and the opposite wall of air jet. The relative locations of filaments would vary widely on these two places in interlacer. As a result, useful interlacing process may be done there.(4) As mentioned above, we obtained the guides to high quality and efficiency interlacing process. (I) There is a certain optimum value of an air flow velocity. The surplus air flow velocity is not useful for efficient interlacing process. (ii) The drag of a filament that contributes to the interlacing process depends widely on the geometry of an interlacer.