Experimental investigation on fluid mechanics of micro-channel heat transfer devices

The future technological horizons for engineering applications (Automotive, Energy, Bio-Engineering) require the use of limited size heat exchangers with high efficiency. In the present work, the flow field in small scale channels of different geometries is investigated experimentally using µPIV (micro Particle Image Velocimetry) and thermal measurements. The Reynolds number in the channels is changed as also the wall temperature, in order to investigate and improve the thermal efficiency at different flow rates, temperatures and geometrical configurations. The main result of this investigation is that a serpentine cell attains the highest efficiency regardless of flow regime, getting high Nusselt numbers combined with low pressure losses, as derived by the observation of quite high local velocities and few recirculation regions.