TITLE : HOTBOX EXAMPLE : ELECTRONIC COOLING WITH HEAT SINK

BY : CHAM Development Team - F Liu DATE : 1999 FOR : Demonstration Case PHOENICS Version : HOTBOX VR Notes : Three-dimensional, steady flow, Natural convection, Cartesian computational grid

Description of the problem:

- The unit is sealed by an aluminium back casting incorporating a heat sink and a plastic cover, and is mounted on a wall with the fins being aligned with gravity, click here to see View of electronic unit; and
- There are 9 heated components and two transmitter/receiver cans on the main board, click here to see Detail of main board.
Solution procedure:

- The solution domain is enlarged so that the surrounding air is modelled;
- Flow is assumed to be laminar;
- Ideal gas law is employed and the buoyancy effect is included using Density-Difference method; and
- Pressure-relief objects are used in several sealed enclosures.

Pictures are as follows :1. Velocity vectors

Velocity vector at plane z=0.032

Velocity vector at plane z=0.032 (enlarged)

Velocity vector at plane z=0.0616

Velocity vector at plane z=0.0616 (enlarged)2. Temperature contours

Temperature contour at plane z=0.032

Temperature contour at plane z=0.032 (enlarged)

Temperature contour at plane z=0.0616

Temperature contour at plane z=0.0616 (enlarged)