核电磁脉冲双层开孔矩形腔体屏蔽效能研究

Study on the Shielding Effectiveness of Rectangular Double-deck Cavity under HEMP

针对开孔的双层屏蔽腔体特点,采用传输线理论,建立了核电磁脉冲平面波照射下计算双层腔体屏蔽效能的等效电路模型,推导了近似计算的解析解,与仿真计算结果进行了对比,并计算分析了双层腔体两孔的相对位置、孔间距对屏蔽效能的影响。结果表明:两孔在偏离状态下泄漏进腔体内的电磁能量最少,屏蔽效能最高;两孔之间的距离增大,腔体的屏蔽效能和谐振频率随之变大。解析解与仿真计算的结果较为一致,验证了解析方法的有效性,为工程中快速计算双层腔体屏蔽效能提供了有效的参考。

According to the characteristics of the double-layered shielding cavity with open hole, the transmission line theory ( TLM) was used to establish the equivalent circu让 model for calculating the shielding effectiveness under HEMP ( High Altitude Nuclear Electromagnetic Pulse) plane wave irradiation, and the approximate calculation was deduced. The approximate results were compared with the simulation calculation results, and the influence of the relative positions of the two holes and the distance between the holes on the shielding effectiveness was analyzed. The results show that the electromagnetic energy is the least and shielding effectiveness is the highest with the two holes in the deviated state leak into the cavity;when the distance between the two holes increases, the shielding effectiveness and resonant frequency of the cavity become bigger. In addition, the approximate results and the simulation results are consistent, which verify the validity of the approximate calculation. It provides an effective reference for quickly calculating the shielding effectiveness of double-deck cavity in engineering.