Novel flow visualization and extensive controlled heat transfer enhancement studies have been conducted to help understand and characterize the corona wind-augmented natural convection process from a vertical heated copper plate subject to a reversible polarity DC high-voltage electric field at various constant heating fluxes. The first part of the paper discussed single electrode results and corona discharge mechanisms and their impact on the heat transfer enhancement phenomenon. This second part will address flow visualization and multiple electrode studies. The effects of varying a series of parameters coupled with a range of electrode voltages have been investigated, and the trends associated with these experiments are discussed in the presence of single and a variety of multiple electrode configurations. Novel particle entrainment technique, videography, and Schlieren studies have yielded a body of visualization results that throw light on the complex mechanism of heat transfer enhancement actuated by the corona wind, and its similarity with a submerged jet is shown by these observations. Optimization of heat transfer enhancement in terms of electrode numbers and configuration can be attained, and this could lead to better design of devices employing such techniques.
Enhanced Heat Transfer
Volume 9, 2002 - Issue 5-6