Cooling performance of a teardrop cross-section Kagome truss-filled array jet impingement composite cooling structure

Abstract

The target surface is coupled to truss rods and the jet space to form a robust overall structure using 30 Kagome truss cores with 5 × 6 array configurations. This paper focuses on the cooling performances of the array jet impingement structure with the Kagome truss array in a 3D printing heat exchanger at Reynolds numbers (Re) ranging from 5000 to 50,000. The cooling characteristics of the Kagome truss-filled array jet impingement with a circular cross-section (CC) and a teardrop cross-section (TC) are comparatively studied through experiments and numerical simulations. The effects of the truss array arrangements, the diameter of the cross-section (d) and the trailing edge angle (α) on the cooling characteristics are studied by numerical simulation in the TC, where the truss array arrangements include an in-line arrangement and a staggered arrangement, d = 1–3mm and α = 45°–90°. The results indicate that when d is 3 mm and α is 45°, the TC has better cooling performance compared to the CC. The TC in the staggered arrangement has a smaller pressure loss coefficient (Cp), while that in the in-line arrangement has a higher average Nusselt number on the impingement target surface (Nuave). The comprehensive thermal factor (F) is increased by 6.58%–21.00% with the increase in d from 1 mm to 3 mm and decreased by 7.16%–8.90% with the increase in α from 45° to 90° in the TC. Two empirical correlations for the Nuave and the Cp for the TC have an accuracy of about 5%.