Seminar

A journey to understand thermo-hydrodynamic coupling in cooling technology for high-heat-flux device

Prof. Aejung Yoon

ABSTRACT

Thermal management of high-heat-flux electronic devices has recently become one of the most challenging problems in the latest industry. A pulsating heat pipe (PHP), has received attention in recent decades as a promising solution for systems with local hot spots. Due to its simple geometric structure and ability to handle high-heat-flux loads, it has been used in a variety of applications including electronic devices, solar collectors, and satellite equipment. The PHP consists of a meandering capillary tube filled with a working fluid, distributed in the form of liquid slug/vapor plug bundles showing thermally-driven oscillation. The thermal performance of the PHP is mainly affected by its flow characteristics under thermo-hydrodynamic coupling. Therefore, an in-depth investigation on the thermally-driven flow inside the PHP is necessary. In this study, a systematic investigation is performed to understand the thermo-hydrodynamic coupling in PHPs. As a first step, a flow visualization is performed using high-speed photography together with our image-processing algorithm. Then, a numerical simulation is conducted to find a link between the heat input and flow behavior of PHPs. Based on the experimental and numerical data, a theoretical model is proposed to quantitatively explain the operating mechanism of PHPs. Based on the model, further investigations are carried out to optimize the thermal performance or to provide a design guideline of PHPs.