Numerical simulation and experimental investigation for design of a carbon fiber tow pneumatic spreading system

The work successfully designs a high efficient carbon fiber pneumatic spreading system. The internal flow field of the fiber pneumatic spreader was first simulated by solving Reynolds-averaged Naiver Stokes equations, and the characteristics of the flow pattern in the spreader under various operation conditions were analyzed in terms of the mass flow rate and the velocity distributions. Comparisons of numerical results with measured velocity and pressure distributions were made to determine the accuracy of the employed method. A good agreement was found in both qualitative and quantitative analysis. A new variable, spreading evenness, was defined to specify the dispersing extent of fibers in a carbon fiber tow during the fiber pneumatic spreading process. By the spreading evenness, a quantitative comparison of a spread carbon fiber tow can be made and the optimum condition can be easily obtained at fiber spreading experiments. The dispersing mechanism of a carbon fiber tow was comprehensive by the computational modeling and the spreading experiment. The performance of the fiber tow pneumatic spreader system was better than prior studies, and the use of numerical analysis combined with the fiber spreading experiment was useful for the development of the fiber pneumatic spreading system. (C) 2005 Elsevier Ltd. All rights reserved.