적외선 신호 감소를 위한 가스 터빈 엔진의 배기 노즐 유동 특성에 관한 연구 = A Study on Exhaust Nozzle Flow Characteristics of Gas Turbine Engine for Infrared Signature Reduction

다국어 초록 (Multilingual Abstract)

The flow characteristics of the plume ejected from a micro-jet engine's rectangular exhaust nozzle have been studied by conducting experimental and numerical analyses. The radiated infrared signature of a plume ejected from a rectangular exhaust nozzle with a large aspect ratio in a jet propulsion engine is known to be significantly lower than that of a plume ejected from a circular exhaust nozzle. The velocity and temperature distributions, which are the flow characteristics of the jet, were measured to investigate this phenomenon. For this purpose, we installed a circular nozzle and a rectangular exhaust nozzle with an aspect ratio of five to a micro-jet engine. The results showed that the plume spreads wider as it moves away from the nozzle exit and that the velocity rapidly decreases in the case of the rectangular nozzle, contrary to the case of the circular nozzle. Similar tendencies were observed for the temperature distribution and magnitude of the ejected plume. Thus, we concluded that the flow distribution caused by the nozzle shape induces a greater drop in the radiated infrared signature of the plume ejected from the rectangular nozzle than the circular nozzle. Flow analysis was conducted to evaluate the flow in and outside the exhaust nozzle; results similar to those of the experiment were obtained. These results show that the ejecting jet has a greater mixing effect on the air outside when using the rectangular nozzle than the circular nozzle.

목차 (Table of Contents)

• 제1장 서 론 1
• 1.1절 추진기관 발전 배경 1
• 1.2절 적외선 신호 감소 기술 동향 3
• 제2장 연구 배경 5
• 2.1절 연구 동향 5
• 2.2절 연구 목적 8
• 제3장 실험 방법 및 장치 소개 9
• 3.1절 실험 개요 9
• 3.2절 실험 방법 9
• 3.3절 마이크로 터보제트 엔진 10
• 3.4절 유량 계측 방법 12
• 3.5절 엔진 성능 측정 방법 14
• 3.6절 추력 측정용 지상리그 17
• 3.7절 배기가스 온도 및 속도 측정 18
• 3.8절 적외선 신호 측정 19
• 3.9절 노즐 형상 23
• 제4장 수치 해석 모델 24
• 4.1절 수치해석 모델 25
• 4.2절 경계조건 26
• 4.3절 격자 독립성 및 검증 30
• 제5장 결과 및 토론 35
• 5.1절 엔진 성능 결과 35
• 5.2절 적외선 신호 측정결과 39
• 5.3절 배기가스 속도 및 온도 41
• 5.4절 유동해석 결과 46
• 제6장 결론 및 향후 계획 54
• 제7장 참 고 문 헌 56