コロナ放電を利用した対流伝熱の促進: 流れと平行なワイヤ電極配置に対する実験

This study has been conducted to clarify the mechanism of heat transfer enhancement in a convective field with ionic wind. Experiments were performed in an air channel-flow in which equally spaced positive wire-electrodes were set in parallel to the primary flow direction. The ionic wind was induced by applying electric field to bring about a corona discharge. The visualization of the flow patterns by using smoke-tracer method and the measurements on velocity profiles, friction factor, and heat transfer coefficient were systematically carried out. By combination of the primary flow with the ionic winds, the pairs of counter-rotating longitudinal vortex rolls were created over the wall surface. Heat transfer augmentation utilizing the combined flow was achieved especially in the laminar flow range, being accompanied with an increase in the pressure drop. On the basis of the results, the mechanism of heat transfer enhancement was discussed