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A Study on the Structural Stability of Nozzle Manufactured with 5-axis Machining

5축 가공으로 제작한 노즐의 구조 안정성에 관한 연구

  • Received : 2022.06.03
  • Accepted : 2022.10.10
  • Published : 2022.10.31

Abstract

In this study, 5-axis machining was proposed as a method for manufacturing a nozzle with a curved shape, and flow analysis and structural analysis were used for structural validation of the manufactured geometry. The program used for CFD obtained the internal temperature and pressure distribution of the nozzle using STAR-CCM+ and used it as the boundary condition for structural analysis. For structural analysis, the commercial program NASTRAN was used, and stress was calculated using the von-mises technique. Based on the maximum stress value generated, the safety margin was 0.78 and the safety margin of the bearing stress was 46.8. In addition, the creep life was calculated as 9.97 x 1012 hours using the Larson-Miller parametric method and applying the maximum stress value of 187 MPa and the exhaust gas perfectly mixed temperature of 463 K.

본 연구에서는 굴곡이 있는 형상의 노즐의 제작 방법으로 5축 가공을 제안하였고 제작한 형상의 구조적 검토를 위해 유동 해석과 구조해석을 활용하였다. 유동 해석에 사용한 프로그램은 STAR-CCM+이며 노즐의 내부온도와 압력 분포를 획득하였고 구조해석의 경계조건으로 사용하였다. 구조해석은 상용 프로그램 NASTRAN을 활용하였으며 von-mises 기법으로 응력을 계산하였다. 발생하는 최대 응력 값을 기준으로 안전 마진은 0.78, 베어링 안전 마진 또한 46.8로 안전하였다. 그리고 크리프 수명은 Larson-Miller 변수식 방법을 사용하여 최대 응력 값 187 MPa와 배기가스 완전 혼합된 온도 463 K를 적용하여 예측된 수명 시간은 9.97 x 1012 시간으로 계산되었다.

Keywords

Acknowledgement

이 논문은 국방과학연구소가 지원하는 저피탐무인항공기 추진계통 IR 감소 기술 연구로 수행되었습니다.

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