The performance of various types of silencers used to reduce the micropressure waves radiated from ventilation holes and inclined shafts, which are being studied as measures to reduce micropressure waves in railway tunnels, was evaluated to find an effective silencer. In order to find the optimal silencer, the magnitude and frequency characteristics of the pressure waves emitted from the inclined shaft were analyzed to find an excellent silencer. The evaluation showed that the model with a porous cylinder and a small diameter outer tube was the simplest but performed the best.

Abstract
1. 서 론
2. 축척 모 델 주행시험
    2.1 주행시험 장치 및 소음기 형상
3. 소음기 주행시험 결과
    3.1 속도별 고효율 소음기 통과 미기압파 특성
    3.2 소음기 방식별 미기압파 특성
4. 결 론
후 기
References

• 고태환(Test & Certification Center, KRRI) | Taehwan Ko
• 김동현(Hyper Tube Express (HTX) Research Team, Korea Railroad Research Institute) | Dong Hyeon Kim
• 강부병(Department of Railway Vehicle System Engineering, Woosong University) | Bu-Byoung Kang Corresponding author