Numerical investigation of baffle-enhanced cooling strategies in data center server racks

The escalating computational demand and subsequent heat generation pose a critical challenge for thermal management in modern high-power-density data centers. Non-uniform airflow distribution and localized hotspots within server racks can significantly compromise system reliability and energy efficiency. This study presents a comprehensive numerical investigation on the use of passive exhaust-side baffles to enhance rack-level cooling performance. A validated computational fluid dynamics (CFD) model was employed to simulate a dual-row server rack configuration in which exhaust-side baffles were applied to locally redirect the hot-air flow. The effects of baffle inclination angle (−75° to +75°), baffle length (0.10-0.30 m), and varying rack power densities (5000-10,000 W) were systematically analyzed. Thermal performance was evaluated using Return Temperature Index (RTI) and Supply Heat Index (SHI) as key metrics. Our findings indicate that a baffle with an upward angle of +60° and a length of 0.25 m delivered the most favorable cooling performance, reducing bottom-rack hotspot temperatures and significantly improving airflow uniformity. Under high-load conditions, the optimized baffle configuration decreased RTI by approximately 20% and SHI by up to 0.113, demonstrating its robustness across operational scenarios. The findings confirm that strategically implemented passive baffles can serve as an effective and energy-efficient means to improve thermal reliability in data center environments. Recommendations for future work include the exploration of adaptive baffle systems for real-time thermal optimization.