Study on three numerical models for rack in data center and comparisons with test results

For a row-level data center with 10 racks, both experimental measurements of air temperature distribution and numerical simulations are conducted with three rack models. The test data center is equipped with 384 thermocouples, and hot aisle temperatures (432 sets of temperature data) were mapped after steady state was reached. Three types of rack models—the rack-level black box model (RBBM), the server-level black box model (SBBM), and the server-level porous medium model (SPMM) — were compared. For two typical operating cases, rack inlet deviation for all models was within ± 1 °C, and about 75% of outlet points were within ± 1 °C. The SPMM reproduced hot aisle temperatures most accurately. The agreement was degraded by rack leakage, which makes the inlet consistency worse by 20.3% points and the maximum inlet temperature difference increased by 2.9 °C. Finally, rack model selection guidance for different application purposes is suggested.