The thermal management of high-density electronics within military shelters is a critical challenge for ensuring operational reliability, particularly under harsh field conditions involving significant solar radiation. This study presents a numerical investigation using three-dimensional Computational Fluid Dynamics (CFD) to optimize an air-cooling system for an electronics rack housed in a military shelter. Four distinct cooling configurations were analyzed and compared: (1) a baseline model relying on natural convection, (2) a fan-assisted forced convection model, (3) a direct cold air supply model using an insulated duct, and (4) a hybrid model integrating both fans and the duct. Boundary conditions were established based on the high temperature and solar radiation criteria of the MIL-STD-810G standard. To quantitatively evaluate the cooling efficiency of each system, a normalized performance index derived from a weighted sum of the average temperature and temperature standard deviation was employed. The results demonstrate that the baseline configuration leads to critical overheating, with component temperatures reaching up to 124℃. In contrast, the hybrid fan-duct system exhibited the most superior performance, effectively reducing the maximum temperature to 59℃. This is attributed to a powerful synergistic effect, where the qualitative supply of low-temperature air via the duct is combined with the quantitative distribution of flow rate throughout the system by the fans. This study elucidates an effective thermal management strategy for electronics in military shelters exposed to severe environments, identifying the integrated fan-duct system as the most robust and optimal air-cooling solution.

Abstract
1. 서 론
2. 연구 방법
    2.1 해석 모 델 및 형상
    2.2 수치 해석 방법
    2.3 경계 조건
    2.4 성능 평가 지표
3. 결 과
4. 고 찰
5. 결 론
References

• 강인한(LIG Nex1 Mechanical R&D) | In-Han Kang Corresponding author
• 김태윤(LIG Nex1 Mechanical R&D) | Tae-Yoon Kim
• 오창엽(LIG Nex1 Mechanical R&D) | Chang-Yub Oh
• 라영은(LIG Nex1 Mechanical R&D) | Yeong-eun Ra