computational fluid dynamics (CFD)

Computational fluid dynamics (CFD) is the use of applied mathematics, physics and computational software to visualize how a gas or liquid flows -- as well as how the gas or liquid affects objects as it flows past. Computational fluid dynamics is based on the Navier-Stokes equations. These equations describe how the velocity, pressure, temperature, and density of a moving fluid are related.

Computational fluid dynamics has been around since the early 20th century and many people are familiar with it as a tool for analyzing air flow around cars and aircraft. As the cooling infrastructure of server rooms has increased in complexity, CFD has also become a useful tool in the data center for analyzing thermal properties and modeling air flow. CFD software requires information about the size, content and layout of the data center. It uses this information to create a 3D mathematical model on a grid that can be rotated and viewed from different angles. CFD modeling can help an administrator identify hot spots and learn where cold air is being wasted or air is mixing.

Simply by changing variables, the administrator can visualize how cold air will flow through the data center under a number of different circumstances. This knowledge can help the administrator optimize the efficiency of an existing cooling infrastructure and predict the effectiveness of a particular layout of IT equipment. For example, if an administrator wanted to take one rack of hard drive storage and split the hard drives over two racks, a CFD program could simulate the change and help the administrator understand what adjustments would be need to be made to deal with the additional heat load before any time or money has been spent.

See also: power usage effectiveness (PUE)