Numerical Simulations of Plane-Wall Coanda Effects for Control of Fiber Trajectories in the Melt-Blown Process

The goal of this investigation is to demonstrate, by means of numerical simulation, that the Coanda effect can be used to affect the trajectory of fine fibers created by the melt-blown process. The Coanda effect serves to modulate the direction of fluid motion, and, in turn, the change in the pattern of fluid flow alters the fiber trajectories. Primary focus is accorded to the use of plane walls to induce the Coanda effect, but some consideration is given to curved Coanda-inducing walls for comparison purposes. The lateral standoff distance between the location of the fiber exit from the die and the Coanda-inducing wall was varied parametrically. The range of standoff distances for which the presence of a plane wall induced the Coanda effect was determined. Another outcome of general significance is that the Coanda effects induced by a curved wall and a plane wall are of comparable magnitude.