Heat transfer performance of boiling jet array impingement on micro-grooved surfaces

Jet array impingement heat transfer is investigated for two phase forced convection of water at atmospheric pressure and subcooling of 7 °C with flow rates up to 660 mL/min. A jet array consisting of nine 1 mm jets with 5 mm inter-jet spacing and a 2 mm jet to target spacing was employed to cool a 15 mm by 15 mm heated surface. A linear micro-groove and a radial micro-groove surface were investigated and compared to a flat surface. The results show that the heat transfer performance of the impinging jet is insensitive to Reynolds number for fully developed boiling. A maximum heat transfer coefficient of h = 230 kW/m2 K was achieved with the radial micro-groove surface, transporting a substantial heat flux of 380 W/cm2. This was a 2.3-fold improvement compared with the flat surface. The linear micro-groove surface also performed well, achieving a 2-fold enhancement. Finally, the performance of the jet array impingement onto micro-grooved surfaces is compared with other recent compact water cooled two phase heat exchanger concepts from the recent literature showing comparable thermal performance.