Cooling performance evaluation of impingement jet cooling passage on solid-state power amplifier in RF system

As the performance requirement for the X-band radar for military use increased, the X-band radar has come to consist of many Transmit/Receive (T/R) modules. So then, the importance of the cooling system is increasing significantly to ensure the operations of the radar during military action. However, satisfying the required cooling performance with the simple square cooling channel is difficult. This study proposes a two-layer cooling channel with the impinging jet array in the T/R modules to overcome the limitation of the existing cooling channel. This two-layer cooling channel was designed to discharge the cooling flow after cooling the individual T/R module to maximize the cooling performance. The cooling performance was evaluated under various mass flow conditions through Ansys Fluent v19.5. The boundary conditions were based on the actual T/R module, and the cooling performance was calculated by pressure drop and convective heat transfer coefficient on the cooling channel. The cooling performance of the two-layer cooling channel was higher than that of the square cooling channel. In particular, the cooling performance was improved up to 4.5 times under low mass flow conditions. The cooling performance was improved by improving convective heat transfer and by increasing the heat transfer area. It is expected that the detection range and resolution can be enhanced when the two-layer cooling channel is applied to X-band radar in the future.