Study of flow and heat transfer characteristics of a liquid jet impinging on a heat sink with discontinuous staggered ring ribs.

• Jet impingement on a heat sink with discontinuous staggered ring ribs is proposed. • The secondary flow enhances the heat transfer in the wall jet region. • The ring-ribbed structure greatly improves temperature uniformity of the heat sink. The temperature uniformity of the bottom surface of the heat sink is one of the hot research topics in the field of jet impingement heat transfer enhancement. In this study, jet impingement on a heat sink with novel discontinuous staggered ring ribs in the wall jet region is put forward to improve the local heat transfer by combining a single micro-jet impact with the secondary flow channel. The flow and heat transfer characteristics of the confined liquid jet impinging on the ribbed head sink under different structural parameters of ribs and jet Reynolds numbers are numerically studied. The V2F turbulence model is used for numerical calculation and the obtained results are compared with the experimental results. The results show that discontinuous staggered ring ribs in the wall jet region of the heat sink promote the formation of secondary flow and strengthen the fluid-solid conjugate heat transfer, that effectively improve the temperature uniformity of the entire heat sink. The temperature difference of the ring-ribbed heat sink is about 91.82% lower than that of the flat plate heat sink when the Reynolds number is 8000. When the outlet shrinkage ratio decreases, or when the position radius of the first layer of ribs or arc angle of a rib on the first layer increases, the temperature uniformity of the ring-ribbed heat sink is gradually improved. However, the lifting range of the outer edge of the heat sink decreases. Also, when the jet Reynolds number increases to 20,000, the maximum temperature difference of the heat sink decreases down to 1.6 K. [ABSTRACT FROM AUTHOR]