Optimising thermal performance in data centre server racks via a parametric layout configuration study

The rapid expansion of data centres has intensified the demand for low-threshold thermal optimisation strategies that avoid the high costs and operational disruptions associated with conventional infrastructure retrofits. This study focuses exclusively on in-rack server layout adjustments, specifically server power combination, arrangement methods, and air supply velocity. A dedicated experimental platform was constructed to represent a standard server rack environment, and physical single-factor and orthogonal experiments were conducted to evaluate cooling efficiency. Results indicate that: (1) Heat accumulates primarily at the rack top, producing pronounced temperature stratification. (2) The relative impact of the examined parameters on thermal performance ranks as follows: air supply velocity > power combination > arrangement method. (3) An optimal configuration-400 W × 10 servers positioned in the lower rack with an air supply velocity of 4 m/s-effectively alleviates heat imbalance and suppresses hot-spots. Compared with a non-optimised baseline, this configuration yielded measurable improvements in airflow utilisation and thermal uniformity. This work demonstrates that strategic in-rack layout adjustments alone can markedly enhance cooling performance without additional capital investment or infrastructure modifications, offering actionable guidance for data centre operators seeking practical, low-effort optimisation measures.