Counter-Flow Ionic Wind for Heat Transfer Enhancement

The increasing complexity of electronic devices and components challenges conventional cooling techniques. For continued development in the electronics field, innovative cooling techniques are required. This thesis examines heat transfer enhancement of a heated plate experiencing low-velocity forced convection. A wire-to-rod corona discharge electrode configuration was used to generate a counter-flow ionic wind so as to direct the bulk gas flow in such a manner as to induce hot spot cooling. Particle image velocimetry (PIV) studies were conducted to profile the interaction between the bulk flow and counter-flow ionic wind and show how the hydrodynamic interactions result in a downward flow towards the heated surface and characteristic recirculation zones. This impingement-like effect enhanced the convection cooling of the heated plate, reducing the temperature by as much as 5 K. Convection coefficient was enhanced by up to 36% in the heat transfer experiments. In the PIV experiments, seeding particles were used to obtain the fluid flow profile. As corona discharge creates a charged environment, seeding particles may get charged, and this may result in deviation from fluid flow due to Coulombic forces on the particles. To ensure the fidelity of the PIV results in these experiments, a simplified particle tracking analysis was conducted, solving the modified Basset-Boussinesq-Oseen (BBO) equation for particle motion and including charging and electric field effects to simulate the effects of corona discharge. The results obtained from these simulations were used to affirm the validity of the PIV results.