ISSN Online: 2377-424X
ISBN Print: 1-56032-797-9
International Heat Transfer Conference 11
ENHANCEMENT OF HEAT TRANSFER BY CHAOTIC ADVECTION IN A SINGLE SCREW EXTRUDER WITH A STAGGERED FLIGHT GEOMETRY
Abstract
The concept of chaotic advection or Lagrangian turbulence is used in establishing enhancement of heat transfer and mixing in a single screw extruder with a staggered flight geometry. The flow inside the channel is assumed to be two-dimensional and three-directional. Under the assumption of Newtonian fluid and Stokes flow, the cross-channel flow velocities are obtained by using the finite difference method. From these numerical solutions and the series solution for the down-channel velocity component, trajectories of passive particles are then obtained to visualize the Poincare map as well as to compute the Liapunov exponent. It is shown that a staggered flight geometry indeed provides a chaotic stirring, or well-mixing property. This geometry further enhances the heat transfer characteristics. The enhancement effect increases as the channel aspect ratio(depth/width ratio) increases.