Single- and Two-Phase Particle Image Velocimetry Characterization of Fluid Flow Within a Liquid Immersion Cooled Electronics Module

With the growth and acceptance of liquid immersion cooling as a viable thermal management technique for high performance microelectronics, fundamental questions regarding the nature of the flow within the system will need to be addressed. Among these are how the coolant is directed toward components of primary interest as well as how other elements within the electronics package may affect the delivery of fluid to these more critical locations. The proposed study seeks to experimentally address these issues with particle image velocimetry (PIV) measurements of unheated and heated flow within an electronics enclosure. The effectiveness of three flow distribution designs at delivering coolant to elements of importance, in this case 6.45 cm² (1 in.²) components meant to simulate processor chips, has been examined using the vectors yielded by the PIV experimentation in a control surface analysis around these critical components. While these previous scenarios are unheated, two-phase PIV has also been conducted with FC-72 as the working fluid while boiling is taking place. A control surface analysis around all four heated elements within the enclosure shows an expected roughly monotonic increase in the net liquid flow rate to the boiling elements as the power applied to them is increased. Additionally, discretized mapping of how the fluid is entering the area surrounding these boiling elements has been constructed to offer insight into how passive elements should be placed within an electronics enclosure so as to not obstruct or hinder the vital flow of coolant to the most critical components.