Numerical Investigation on Air Distribution of Cabinet with Backplane Air Conditioning in Data Center

The effect of gradient exhaust strategy and blind plate installation on the inhibition of backflow and thermal stratification in data center cabinets is systematically investigated in this study through numerical methods. The validated Re-Normalization Group (RNG) k-ε turbulence model was used to analyze airflow patterns within cabinet structures equipped with backplane air conditioning. Key findings reveal that server-generated thermal plumes induce hot air accumulation at the cabinet apex, creating a 0.8°C temperature elevation at the top server’s inlet compared to the ideal situation (23°C). Strategic increases in backplane fan exhaust airflow rates reduce server 1’s inlet temperature from 26.1°C (0% redundancy case) to 23.1°C (40% redundancy case). Gradient exhaust strategies achieve equivalent server temperature performance to uniform exhaust distributions while requiring 25% less redundant airflow. This approach decreases the recirculation ratio from 1.52% (uniform exhaust at 15% redundancy) to 0.57% (gradient exhaust at equivalent redundancy). Comparative analyses demonstrate divergent thermal behaviors: in bottom-server-absent configurations, gradient exhaust reduces top server inlet temperatures by 1.6°C vs. uniform exhaust, whereas top-server-absent configurations exhibit a 1.8°C temperature increase under gradient conditions. The blind plate implementation achieves a 0.4°C top server temperature reduction compared to 15%-redundancy uniform exhaust systems without requiring additional airflow redundancy. Partially installed server arrangements with blind plates maintain thermal characteristics comparable to fully populated cabinets. This study validates gradient exhaust and blind plate technologies as effective countermeasures against cabinet-scale thermal recirculation, providing actionable insights for optimizing backplane air conditioning systems in mission-critical data center environments.