S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Mechanical Aerospace Engineering (기계항공공학부) Others_기계항공공학부
정적, 동적 출구조건에서의 초음속 흡입구 유동진동 해석 연구
NUMERICALL STUDY OF FLOW OSCILLATION AROUND SUPERSONIC INTAKE UNDER STATIC AND DYNAMIC THROTTLING CONDITION
- 홍우람; 김종암
- Issue Date
- 한국전산유체공학회 2010년도 추계학술대회, pp. 26-32
- 공학; 압력진동; Pressure Oscillation; 버즈; Buzz; 초음속 흡입구; Supersonic Intake; 정적 출구조건; Static Throttling Condition; 동적 출구조건; Dynamic Throttling Condition
- Ramjet engine has small throttling ratio in initial launching state and pressure around the engine oscillates in high frequency. Moreover, at that time, throttling ratio is changed abruptly. The flow unsteadiness from throttling ratio changing could bring result in engine unstart or even structure damage to engine. A numerical study was conducted to simulate the pressure oscillation phenomenon that is occurred in small throttling ratio. Simulation and analysis of flow charateristics are not only nuder static throttling condition but also under dynamic throttling condition. Generally, throttling ratio is defined as ratio of throat area and exit area. Throttling ratio 0.70 is threshold between high frequency boundary and low frequency boundary in the present geometry research. Numerical simulation is conducted in 0.55 throttling ratio case and 0.00 that is below 0.70. By the way, the result shows high frequency oscillation between 300 and 400 Hz. Dynamic throttling condition is assumed that throttling ratio can be moved in the range between 0.00 and 0.70. Numerical analysis and discussion of result is conducted for the changing of flow oscillation characteristics under the dynamic throttling condition from the initial condition that pressure oscillation has been already onset.