HEAT-TRANSFER ENHANCEMENT OF LAMINAR AND TURBULENT PIPE-FLOW VIA CORONA DISCHARGE

The effect of corona discharge on forced-convection heat transfer in a tube is studied experimentally. Results are reported for parametric values of the Reynolds number (1000-15 000), electric field potential (0 kV to near spark-over potential), and number of electrodes (single or double electrode configurations). The working fluid in all experiments is air. It is found that heat transfer enhancements are significant only in the laminar and transitional flow regimes when using a single electrode. On the other hand, with a two-electrode configuration, enhancements extend to the turbulent flow regime as well. At constant pumping power higher enhancements are generally associated with the double electrode configuration. The only exception to this is for the fully laminar Reynolds numbers and at the highest field potentials, where the single electrode results exceed those of the double electrode.