CFD-simulation of the filament interactions in the air-texturizing process

The description of the fiber motion in air flow is important for some processes in textile industry that is based on the air-fiber flow. One of the most significant textile processes which used for producing the textile fabrics in many industries is the air-texturing process. This is because of the new technical characteristics which this process adds such as increasing the durability of the fabrics, particularly flat-woven fabrics and this process also provided answers to many of the problems of consistent quality and durability encountered with other yarn technologies. One of the applications of air-texturing process is the use of textile products for vehicle trim areas which has a relatively recent history. The high technical requirements placed on all items in vehicles by the automotive industry such as temperature resistance, high tenacity and high modulus have ensured that air-texturing fiber or yarn used in some automotive industry applications such as tiers, high-pressure hoses, belts, air bags, fastening devices. The present study aimed to make a numerical model for air-fiber flow to investigate the fiber motion in air flow which can be extended to study multifilament interaction in air-texturizing process by considering the contact force and friction between the filaments. The model is based on the theoretical and numerical study of the air-fiber flow. This paper proposes a three-dimensional model for the simulation of the dynamic behavior of multiple flexible fibers in a wall-constrained fluid flow of high Reynolds. The fibers will be modeled as chains of cylindrical segments which each segment mass is represented as a mass point. Along the series of fiber mass points, the drag forces, the elongation forces, the elastic bending and the segment inertia are considered which the fibers motion can be described by the translational equations at each mass point with considering the fiber-wall interaction. The model consists of a MATLAB programming language for the filament model and a complex 3-D simulation program such as FLUENT for CFD simulation of fluid domain and a coupling model in MATLAB as an interface to couple the MATLAB and FLUENT together. Finally, the study proposes an air box flow domain with a moving wall to make a vortex inside the box to test the model and provide the trajectories of the fiber in this fluid domain.