Investigation on flow and heat transfer performance of avionic computer with submerged jet impingement cooling

Abstract This study focuses on investigating the flow distribution and heat transfer characteristics of submerged jet cooling in avionic computer. A comprehensive analysis of flow and heat transfer performance under varying inlet velocity (Vinlet) and inlet temperatures (Tinlet) is conducted using three-dimensional numerical simulations. The temperature and streamline distributions reveal that all server modules exhibit similar flow field structures across different Vinlet and Tinlet conditions. The flow within the server model can be distinctly divided into three regions: the flow convection region, the jet impingement region, and the cross-flow region. Both pressure drop, average and hotspot heat transfer intensities, and thermal resistance exhibit a positive correlation with Vinlet, increasing progressively with higher flow velocities. In contrast, Tinlet has minimal influence on the overall flow and heat transfer performance, indicating that it is not a dominant factor in avionic computer's thermal behavior. The most favorable average heat transfer performance is achieved at (Vinlet = 10m/s, Tinlet = 30°C) condition, where the average temperature and average Nusselt number reach 38.7°C and 9.96, respectively. Given that Tinlet exceeding 60°C combined with Vinlet below 6m/s represents the upper operational threshold, maintaining Tinlet and Vinlet below this limit is critical to ensuring stable operation of critical components. Furthermore, an optimal operational window (Tinlet = 30–40°C and Vinlet = 2-8m/s) is identified, within which the avionic computer achieves the best balance between cooling effectiveness and pumping efficiency, thereby providing direct guidance for avionic computer design optimization.