Novel flow visualization and extensive and controlled heat transfer enhancement studies have been conducted to help understand and characterize the corona wind-augmented natural convection process from a vertical copper plate subject to a reversible polarity DC high-voltage electric field at various constant heating fluxes. The second part of the paper will address visualization studies such as particle entrainment, videography and Schlieren photography, and heat transfer enhancement employing multiple electrodes in a variety of configurations. Both positive and negative polarity DC high-voltage power supply at various heating fluxes was employed. The effects of varying a series of parameters coupled with a range of electrode voltages and its polarity have been investigated, and the trends associated with these experiments are discussed. Single electrode configurations were investigated to understand their impact on the enhancement phenomenon. Electric field strength had a direct and significant influence on the enhancement scale, and extremely high values of enhancement ratios have been recorded. Polarity change of the applied field did not produce much significant influence on the enhancement ratio, although the number of tests performed has been limited. A detailed discussion on the structure and mechanism of the corona discharge and its subsequent impact on the heat transfer is also presented.
Enhanced Heat Transfer
Volume 9, 2002 - Issue 5-6