Using Computational Fluid Dynamics for （使用计算流体动力学）.pdf

This article appeared in the International Journal of Heating, Ventilation, Air-Conditioning, and Refrigeration Research, Volume 9, Number 2, April 2003, pp. 153- 166. Use of Computational Fluid Dynamics for Calculating Flow Rates Through Perforated Tiles in Raised-Floor Data Centers Kailash C. Karki, Amir Radmehr, and Suhas V. Patankar Innovative Research, Inc. 3025 Harbor Lane N, Suite 300 Plymouth, MN 55447, USA ABSTRACT This paper describes a Computational Fluid Dynamics model for calculating airflow rates through perforated tiles in raised-floor data centers. The model is based on the assumption that the pressure in the space above the raised floor is uniform, which allows the calculation to be limited to the space below the raised floor. It uses a finite-volume method, the k-ε turbulence model, and a multigrid method. The model is applied to a real-life data center. The calculated results for velocity and pressure distributions are discussed. The flow rates through the perforated tiles are shown to be in good agreement with the measured values. INTRODUCTION Airflow Distribution in Data Centers Data centers are used to house computer servers, telecommunications equipment, and data storage systems. The equipment, which dissipates a significant amount of heat, must be maintained at acceptable temperatures for reliable operation. The heat load can vary significantly across the computer room, and it changes with addition or reconfiguration of hardware. Therefore, to prevent equipment failure, just meeting the total cooling capacity or airflow requirement is not sufficient; special attention must be paid to the distribution of the cooling air. Most data centers use the under-floor plenum below a raised floor to supply cold air to the equipment. The computer room air conditioner (CRAC) units push cold air into the plenum, from where it is introduce