NON-NEWTONIAN FLOW AND HEAT-TRANSFER IN AN OBSTRUCTED CHANNEL WITH RADIOFREQUENCY HEATING

The hydrodynamic and thermal conditions associated with the flow of a non-Newtonian fluid (polystyrene), which is heated volumetrically by e lectric radio-frequency excitation, is considered. The fluid is forced through a two-dimensional channel having local, stationary blocks, wh ich restrict the flow and are maintained at a constant rms voltage pot ential. Detailed and overall system response is examined for a range o f fluid velocities, restriction sizes, and radio-frequency heating rat es. This heating reduces the pressure drop induced by the restriction and alters the flow structure, suggesting that it may be used to contr ol and augment augment conventional injection molding operations.