Computer Room Air Conditioning: DPM

Computer Room Air Conditioning CFD Simulation, DPM

Description

This project simulates air conditioning within an office housing several computers and simulators, using ANSYS Fluent. The air conditioning system combines floor heating with ceiling cooling — a configuration where the buoyancy effect drives free heat transfer throughout the space: hot air rises from the floor toward the ceiling due to its lower density, while cooler air sinks in the opposite direction, establishing a circulating flow that sustains the office's air conditioning process.

Airflow enters the office through circular sections at 0.6125 m/s and 291.1 K, exiting through rectangular sections on the ceiling at atmospheric pressure. The 3D geometry was designed in Design Modeler, representing an office space measuring 6.35 m by 5.4 m at floor level and 2.7 m high, containing 4 computer cases and 4 simulators positioned as internal heat sources, alongside the floor and ceiling air inlet/outlet sections. The domain was meshed in ANSYS Meshing using an unstructured grid totaling 3,089,035 elements.

Methodology

Given the radiant heat transfer occurring between surfaces within the office, a radiation model was included in the simulation. Particles were also defined using the Discrete Phase Model (DPM) at the inlet sections, enabling study of airflow behavior and the resulting circulation pattern throughout the office interior.

The 4 computer cases and 4 simulators each generate heat as part of their normal operation, transferring it into the surrounding space. The computer cases were assigned a heat flux boundary condition of 152.5 W/m², while the simulators were assigned 90.56 W/m².

Conclusion

Results include 2D and 3D contours of pressure, velocity, and temperature, along with 3D velocity vectors throughout the office. Examining the tracked particles' behavior and displacement patterns provides direct insight into the resulting airflow circulation — confirming how the combined floor-heating, ceiling-cooling configuration, radiant heat exchange between surfaces, and internal equipment heat loads together shape the office's overall thermal and airflow environment.