Effect of metal plate barrier without holes in forced convection of electronic equipment

Abstract

Two rectangular block-like elements as in an electronic module are positioned in a parallel-walled channel and cooled by forced convection airflow. A metal plate without holes as a barrier protrudes above the plane of the modules. It is intended to function as a cover for protecting them from mechanical or electromagnetic damage, or as a thermal control device. Per-module heat transfer coefficients in the presence of the barrier of various gaps, G, between the barrier and the channel and distance, L, between the module and the barrier were measured. In the presence of the barrier, the heat transfer coefficient at the 2nd row module is enhanced, but it is diminished at the 1st row module. Nusselt numbers are correlated as a function of Reynolds number and G/L.

The effect of a metal plate barrier with circular holes in the forced convection of electronic equipment

“…Therefore, the 2nd module was in a reattachment zone, which enhanced its heat transfer performance. However, in the case of the barrier with circular holes, the tuft did not vibrate violently, but gently, similar to the case with no barrier [8]. As shown in Fig.…”

“…3. Relation between Re and Nu bi /Pr 1/3 using a barrier without holes [8]. exceed unity for either module so the barrier with circular holes reduced the heat transfer of the modules.…”

“…An attempt was made to correlate the experimental results using the dimensionless number G/L, without success, whereas in the case of the barrier without holes, the experimental results were well correlated using G/L [8]. In the case of the barrier with circular holes, the heat transfer performance of the module is strongly influenced by the air flow thorough the holes of the barrier.…”

“…Heat loss from each module to the air gap was estimated by the temperature difference (T wi -T si ) as shown in Ref. 8. The mean air velocity v in the duct without modules was 0.54 to 2.7 m/s within an uncertainty of ±1%, and was used as the characteristic velocity for the Reynolds number defined in Section 3.…”

“…I previously reported the effect of the metal plate barrier without holes on the heat transfer of the module covered surface [8], in which the heat transfer was enhanced at the 2nd row module, but diminished at the 1st row module.…”