Study on the heat transfer enhancement characteristics of non-uniform aperture jet impingement on electronic components in confined spaces

This study aims to investigate the cooling performance of array nozzles in confined spaces, with a focus on the influence of non-uniform aperture layout on the suppression of thermal spots and the uniformity of the temperature field for electronic components with a heat flux of 125 watts per square centimeter. Using the k turbulence model, numerical simulations were conducted on 27 non-uniform annular aperture configurations. The optimal "484" layout, which consists of an outer ring with a thickness of 0.4 mm, inner ring 0.8 mm, and center 0.4 mm, achieved a peak temperature of 29.5°C. This result represents an 8.6% reduction compared with the uniform "444" configuration, while the surface temperature difference Δ T was reduced by 38.4%. Mechanistic analysis reveals that the enlarged inner-ring aperture generates intense lateral shear-layer interactions with adjacent smaller jets, effectively disrupting the thermal boundary layer and dispersing central hotspots. The temperature uniformity index T δ was improved by up to 34.47% at 500 W compared with the uniform "888" layout. The innovation of this work lies in three aspects: (1) A non-uniform aperture circular array jet arrangement structure was designed. (2) The non-uniform design of the inner ring aperture had the best heat dissipation performance effect in this jet cooling system. (3) Temperature uniformity T δ was introduced as a performance evaluation index for constrained jet cooling, proving that the non-monotonic interval arrangement of aperture gradients is superior to the step arrangement, and the "484" configuration has the best heat dissipation performance.