Journal of the Korean Society of Propulsion Engineers (한국추진공학회지)

The Korean Society of Propulsion Engineers (한국추진공학회)
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Numerical Study on Transfer Port Design for Scavenging Performance in Small Two-stroke Engines

소형 2행정 엔진의 전송 포트 형상에 따른 소기 성능에 대한 수치 해석적 연구

  • Received : 2020.07.21
  • Accepted : 2020.11.10
  • Published : 2020.12.31
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Abstract

In this paper, the scavenging process of various transfer ports was evaluated to improve the performance of a small two-stroke engine for unmanned aerial vehicles. Three-dimensional computational fluid dynamics simulations were performed to four transfer ports for the evaluation, and a three-phase scavenging model was developed and applied to the simulation results for the quantitative comparison of scavenging performance. the short-circuit of fresh charge was restrained and an in-cylinder turbulent kinetic energy was enhanced by changing the transfer port. Also, a difference in the scavenging for each port were confirmed by applying the three-phase model to the simulation results.

본 연구에서는 무인 항공기용 소형 2행정 엔진의 성능 개선을 위해 다양한 전송 포트 형상의 가스교환 성능을 평가하였다. 성능 평가를 위해 네 가지 전송 포트 형상에 따른 3차원 전산 유체 해석을 진행하였으며, 가스 교환 성능의 정량적 평가를 위해 이상적 소기 모델인 완전 대체 소기 모델과 완전 혼합 소기 모델을 바탕으로 새로운 3단계 소기 모델을 개발하여 해석 결과에 적용하였다. 2행정 엔진의 전송 포트 형상 변경을 통해 흡기의 단락 현상을 효과적으로 줄였으며 가스 교환 과정 동안의 실린더 내 난류 에너지 또한 크게 개선되었다. 또한, 전송 포트 형상 별 3단계 소기 모델의 적용을 통해 가스 교환 성능을 정량적으로 평가할 수 있었으며, 포트 형상 별 소기 양상의 차이를 확인할 수 있었다.

Keywords

Acknowledgement

본 연구는 민군협력진흥원의 "민군기술협력사업" 중 "드론용 하이브리드 전원장치(6 kW) 개발"(18-CM-AS-03) 과제 지원으로 수행되었습니다.

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