This paper reviews thermal management challenges encountered in a wide range of electronics cooling applications from large-scale (data center and telecommunication) to small-scale systems (personal, portable/wearable, and automotive). This paper identifies drivers for progress and immediate and future challenges based on discussions at the 3rd Workshop on Thermal Management in Telecommunication Systems and Data Centers held in Redwood City, CA, USA, on November 4-5, 2015. Participants in this workshop represented industry and academia, with backgrounds ranging from data center thermal management and energy efficiency to high-performance computing and liquid cooling, thermal management in wearable and mobile devices, and acoustic noise management. By considering a wide range of electronics cooling applications with different lengths and time scales, this paper identifies both common themes and diverging views in the thermal management community.

Impinging synthetic jets have been identified as a promising technique for cooling miniature surfaces like electronic packages. This study investigates the relation between the convective heat transfer characteristics and the impinging synthetic jet flow structure, for a small jet-to-surface spacing H / D = 2 , dimensionless stroke length 1 < L 0 / D < 22 , and Reynolds number 1000 < Re < 4300 . The heat transfer measurements show evidence for a power law relationship between the Reynolds and Nusselt number for a constant stroke length. A critical stroke length L 0 / H = 2.5 has been identified. Using phase-resolved particle image velocimetry, vortex quantification is applied to elucidate the influence of the impinging vortex on the time-averaged heat transfer distribution.