In order to study the noise propagation characteristics and noise evaluation of military helicopters, this study conducted continuous noise monitoring of 20 noise-sensitive areas within 3 km around a military heliport in South Korea over a period of 5 days, and the results showed that the noise values at the 20 measurement points around the military heliport were lower than the limit of WECPNL 75 stipulated in the standard for civil airports, and it was found that the maximum noise level had the greatest influence on the evaluation indexes. The study found that the maximum noise level has the greatest influence on the evaluation index. At the same time, the analysis of the noise source spectrum shows that the helicopter noise is dominated by low and medium frequencies, and the low-frequency noise is more irritating in a short period of time.

Abstract
1. 서 론
2. 측정지점 및 방법
3. 측정결과 및 분석
4. 결 론
후 기
References

• 장명(School of Mechanical Engineering LanZhou Jiaotong University; China) | Ming Zhang
• 김병삼(Department of Mechanical engineering, Wonkwang University.) | Byoung-Sam Kim Corresponding author