Staggered and In-line Submerged Jet Arrays for Power Electronics Using Variable Area Discharge Manifolds

Abstract

Power electronics packages in electric and hybrid vehicles require dedicated and dynamic cooling to perform reliably. Generally, such packages are designed to spread heat to a large surface area, and employing the radiator flow loop and fluid to provide a more aggressive, liquid-cooling approach to supplement heat spreaders is an appealing idea when considering cost, design, and fabrication. An array of liquid jets is the best single-phase cooling technique for cooling large surfaces. The highest regions of cooling in an array of jets are located at the stagnation points and, to a lesser degree, the fountain regions. One of the more significant issues facing arrays of jets is the degradation of downstream jets caused by the interference of fluid spent by upstream jets. The idea of an angled confining wall to divert the spent flow, and therefore prevent the entrainment of flows, was complemented by investigations into the viability of water-ethylene glycol as a working fluid and staggered arrays. A measurement technique was used to determine the local thermal characteristics for cases of varying jet Reynolds number, plate angle, jet-to-jet pitch, and jet-to-plate height above the surface. Water-ethylene glycol and staggered arrays were compatible and showed improved heat transfer when combined with the angled wall spent fluid management scheme.