No abstract

Experimental measurements of multiple nozzle submerged jet array impingement single-phase and boiling heat transfer were made using FC-72 and 1 cm square copper pin fin arrays, having equal width and spacing of 0.1 and 0.2 mm, with aspect ratios from 1 to 5. Arrays of 25 and 100 nozzles were used, with diameters of 0.25 to 1.0 mm providing nozzle area from 5 to 20 mm2 (5 to 20% of the heat source base area). Flow rates of 2.5 to 10 cm3/s (0.15 to 0.6 l/min) were studied, with nozzle velocities from 0.125 to 2 m/s. Single nozzles and smooth surfaces were also evaluated for comparison. Single-phase heat transfer coefficients (based on planform area) from 2.4 to 49.3 kW/m2 K were measured, while critical heat flux varied from 45 to 395 W/cm2. Correlations of the single-phase heat transfer coefficient and critical heat flux as functions of pin fin dimensions, number of nozzles, nozzle area and liquid flow rate are provided.

No abstract

In this study we have attempted to compare the heat transfer performance of various commonly used fm geometries.Realistic, manufacturable geometries are optimized for minimizing thermal resistance at moderate laminar air velocities. The basis of comparison was chosen to be a circular array of lmm diameter pin fms with a 2mm pitch. The pitch-to-width ratio of the other geometries were chosen to provide equal ratios of fin area to base area. CFD simulations were carried out on a two-dimensional computational domain bounded by planes of symmetry parallel to the flow. The air velocity was in the range of 0.5 to 5Ws. A comparison of heat transfer coefficient and pressure drop is presented.

No abstract