Instability issues in the server room cooling system

Tomasz Kwiatkowski, Piotr Prusinski, Dariusz Zgorzelski, Sylwester Kozioł


Since 2009, the National Center for Nuclear Research in Poland has been constructing its own High Performance Computing
(HPC) Centre under the name S´wierk Computing Centre (CIS´ ). Now, it is ready reaching its target—1 PFLOPS—in December
2015. However at the early operation stage, one of its major problems was the unstable work of the HPC cluster cooling
system, resulting in increased maintenance costs. The main aim of this work is to thoroughly investigate the origin of the
problem and to find the best solution for it based on results from a Computational Fluid Dynamics (CFD) analysis. The
constructors suspected that the oscillations in the flow domain are caused by thermal flow stratification, but something else
was proved. In this paper, a wide range of cases will be analyzed, covering different work regimes of the installation as well
as various geometry modifications. Finally, certain improvement to the current design will be suggested by the CFD Analysis


HPC, computer cluster, efficient cooling, CFD

Full Text:



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