Effect of branching level on the performance of constructal theory based Y-shaped liquid cooling heat sink

•Cooling performance will be improved by increasing of branching level.•Effect of branching level on pressure loss of YLCHS is very small.•Optimal branching level for the proposed YLCHS is suggested at 4.•Relationship of flow rate, branching level, and peak temperature is modeled. Most of heat in data centers is released from electronic chips in servers. Thus, it is more effective to mitigate the heat from electronic chips directly. Furthermore, the cooling load as well as the energy consumption of air conditionings will also be significantly decreased account for the rapid heat removal from electronic chips. The Y-shaped liquid cooling heat sink (YLCHS) has been demonstrated as an effective way to mitigate the heat from electronic chips with specified flow channels. To further optimize the structure of YLCHS, the effect of branching level on the cooling performance of YLCHS based on constructal theory is studied in this paper. By comparing the cooling performances for YLCHSs with 1 to 4 branching level, the relationship between peak temperature and branching level is modelled. The results show that the peak temperature and average temperature of YLCHS are reduced by 28.8% and 13.5% while the number of branching level is increased from 1 to 4, however, the increases of pressure loss for these YLCHSs are lower than 0.04 kPa. Furthermore, the optimal branching level for the proposed YLCHS is determined at 4 by considering the improvement on the cooling performance and the limited size of heat sink.