TITLE : Flow and heat transfer in an electronic cabinet
BY : CHAM Development Team - F Liu DATE : 1999 FOR : Demonstration Case PHOENICS Version : HOTBOX VR
NOTES : Three-dimensional, forced convection, Cartesian computational grid
Description of the problem:
- This case contains six chips mounted on a PCB;
- The cabinet is half cylindrical cross sectional; air is extracted from fan mounted at top and pushed out of the system via a bottom vent, click here to see External structure of the cabinet and Internal structure of the cabinet;
- Each chip has 1 W heat output;
- Fan works at a fixed velocity of 1 m/s; and
- Dimensions of parts are as follows:
Part Dimension (side*side*thickness) (mm) Model thermal conductivity (W/mK) Object type in HOTBOX Cabinet size (half cylinder) Radius of 140, thickness of 70 - Blockage Chip 20*20*5 30 Blockage PCB 140*100 (2-D) - Plate Fan 70*70 (2-D) - Fan Bottom Vent 70*70 (2-D) - Aperture
- Turbulence is modelled by the LVEL method;
- Material properties are imported from the User-defined property file 'Props'; and
- Fixed pressure boundary condition is applied at the bottom vent.
The following figures show the temperature distributions and velocity vectors of the thermal cabinet with six chips each containing 1W within the half-cylinder enclosure.
Temperature contours across the chips
Temperature contours not across the chips
Velocity vectors across the chips
Velocity vectors not across the chips
This case demonstrates how HOTBOX-VR handles
- irregular boundary using cartesian co-ordinates; and
- large disparity in component dimension and thermal conductivity.