로켓추진이 초공동 수중비행체의 항력에 미치는 영향에 대한 수치해석적 연구

다국어 초록 (Multilingual Abstract)

A numerical analysis for supercavitation underwater vehicle is performed using the 'Torcav v2.1'. There are three models. One is only cavitator and another is underwater vehicle without rocket propulsion. The other is underwater vehicle with rocket propulsion. The Fluid used in the analysis is composed of water, vapor and exhaust gas. exhaust gas passing the nozzle of rocket propulsion with high speed is compressible fluid. So this code must perform compressible multiphase fluid. The biggest feature of the supercavitation is re-entrant. Water circulating inside cavity by re-entrant change drag force of underwater vehicle. This phenomenon results in instabillity of vehicle. but underwater vehicle with rocket propulsion extirpate re-entrant by exhaust gas. exhaust gas flow backward until back of vehicle because of the density difference between the gas and the water. gas flowing backward have low density and low speed. So the effect of exhaust gas on vehicle is slight. Exhaust gas passing the nozzle of rocket propulsion form mach disk. Continuously changing position of mach disk changes the drag force of vehicle. However drag changes due to the mach disk is smaller than the change caused by re-entrant.

목차 (Table of Contents)

• 1. 서 론 1
• 1.1 연구의 필요성 1
• 1.2 연구의 목적 및 내용 4
• 1.3 국내·외 연구 동향 5
• 2. 수치해석방법 7
• 2.1 지배방정식 7
• 2.2 경화기체 상태방정식 8
• 2.3 기계적평형에 따른 문제점 해결 10
• 2.4 HLLC Riemann Solver 12
• 2.5 해석모델 및 경계조건 16
• 3. 결과 및 고찰 18
• 3.1 TORCAV 해석 결과 검증 18
• 3.2 캐비테이터만 있는 경우의 초공동 수치해석 결과 23
• 3.3 캐비테이터에 비행체 몸체가 있는 경우 31
• 3.4 캐비테이터가 있는 비행체에 추진기관이 있는 경우 41
• 4. 결 론 55
• 참고문헌 57
• Abstract 60