根据机箱热载荷等边界要求，对密闭机箱中的电子功能模块的热功耗和机箱热稳态下散热表面的热流密度进行了分析和计算。通过计算机箱与外部空气自然对流冷却下的热流密度值来分析机箱的整体散热性能，并将计算结果与空气自然对流散热的热流密度阈值进行比较；在此基础上使用建模软件 UG NX7.5完成机箱的 CAD数字样机建模；使用 ANSYS Icepak有限元热仿真分析软件进行 CFD(计算流体动力学分析)和热仿真分析，完成了机箱参数设定、网格划分，对机箱进行精确的热仿真计算，验证机箱热设计的可靠性，为其他同类电子设备热仿真分析与散热优化设计提供了参考。

According to the identical border requirement of thermal loads in a chassis, the thermal-power consumption of electronic function modules and the heat flux density of a thermal runaway surface at thermal sta. bility state are analyzed and calculated. The integral thermal runaway characteristic is analyzed by calculating the hot flow density value which is from cooled natural convection air between the chassis and outside. And the re. sults are compared with the hot flow density threshold of air natural convection thermal runaway. Based on this, the simulation of CAD numerical sample is completed by simulation software UG NX7.5. CFD and thermal simu. lation analysis are performed by thermal simulation analysis software of ANSYS Icepak limited elements. Param. eters assumption and grids plotting of the chassis are completed. Accurate calculations of thermal simulations are performed to validate the thermal design reliability of the chassis and provide references for thermal simulation analysis and thermal runaway optimum design of other similar electronic equipment.