Electromagnetic Pulse (EMP) Shielding Effectiveness of Waveguide-Below-Cutoff (WBC) Arrays Installed in Generator Exhaust Chimney and its Effects on Gas Velocity

Title & Authors
Electromagnetic Pulse (EMP) Shielding Effectiveness of Waveguide-Below-Cutoff (WBC) Arrays Installed in Generator Exhaust Chimney and its Effects on Gas Velocity
Pang, Seung-Ki; Kim, Jae-Hun; Yook, Jong-Gwan; Kim, Yuna; Kim, Sangin; Kim, Suk-Bong;

Abstract
Characteristics of exhaust from chimney of electricity generator are analyzed based on CFD when Waveguide-Below-Cutoff (WBC) array is installed in order to achieve the certain level of electromagnetic pulse (EMP) shielding. The main purpose is prediction of average and maximum velocity of exhaust. The results reveal that: 1) When the specification of waveguide is given as 80-diameter, 400-length, and the gap of 20 mm, the shielding effectiveness (SE) is 140dB. The average and maximum velocity of exhaust in the chimney with WBC Array can be represented as exponential functions. 2) As the number of WBC increases, the velocity in the chimney dwindles. 3) Under the situation that WBC with 80 mm diameter is located at intervals of 20 mm, the average velocity can be approximated by $\small{25.5344{\times}e^{(-0.0098{\times}N_{WBC})}}$ with input velocity of 15 m/s. In addition, the determination coefficient is 0.915, which is sufficiently high.
Keywords
EMP;CFD;Waveguide;WBC Array;Shielding Effectiveness;Emergency Generator;
Language
Korean
Cited by
References
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Military Standard Sheet, 2005, High-Altitude Electromagnetic Pulse (HEMP) Protection for Ground-based C41 Facilities Performing Critical, Time-urgent missions Part 1 Fixed Facilities.

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W. A. Bereuter and D. Chang, 1982, Shielding effectiveness of metallic honeycombs, IEEE Transactions on Electromagnetic Compatibility, Vol. EMC-24, no. 1.