CHOSUN

로켓엔진 연소기의 연소안정화를 위한 수동제어기구 설계 기준 구축

Metadata Downloads
Author(s)
이중연
Issued Date
2007
Abstract
The objective of the present study is to establish the basic design criteria on passive control devices such as baffle and acoustic-cavity for enhancement of combustion stability in a liquid rocket engine.
The first method is to use a baffle of the passive stabilization devices in order to ensure the combustion stability. In this study, we will use a baffled injector instead of typical baffle. Acoustic damping induced by gap of baffled injectors is investigated numerically, which are installed to suppress pressure oscillations in a rocket combustor. The previous work reported that the baffled injectors showed larger acoustic damping with the gap between injectors. It is simulated numerically in this study and its mechanism is examined. Damping factors are calculated as a function of gap of the baffled injectors and it is found that the optimum gap is 0.1 mm or so. For understanding of the improved damping induced by the gap, dissipation rate of turbulent kinetic energy and vorticity are calculated as a function of the gap. Both parameters have each maximum value at the specific gap and especially, the dissipation rate has the same profile as that of damping factor. It verifies that the improved damping made by the gap is attributed to the increased acoustic-energy dissipation.
The other method is to use an acoustic cavity and Helmholtz type resonator, in particular. The acoustic behavior in combustion chamber with acoustic cavity is numerically investigated by adopting linear acoustic analysis. From the numerical results, tuning frequency and geometric factor of acoustic cavity are found, respectively. Although acoustic stability is ensured from cold condition, gas property will be changed by inflow of gas product in acoustic cavity during a combustion. Inflow of gas product increases gas temperature in an acoustic cavity and brings about change of sound speed. Accordingly, acoustic cavity is redesigned for better tuning.
Alternative Author(s)
Lee, Jung-Yun
Affiliation
조선대학교
Department
일반대학원 항공우주공학과
Awarded Date
2008-02
Table Of Contents
목 차

LIST OF FIGURES ..................................................... iii

LIST OF TABLES ...................................................... v

NOMENCLATURE ..................................................... vi

ABSTRACT ............................................................. viii

제 1 장 서 론 ......................................................... 1
제1절 연구의 필요성 .............................................. 1
제2절 연구 목적 .................................................... 3

제 2 장 지배방정식과 수치해석 방법 ............................ 4
제1절 지배방정식 .................................................. 4
제2절 해석대상 연소실 사양 .................................... 5

제 3 장 음향학적 고찰과 계산전략 ............................... 9
제1절 배플형 분사기의 음향학적 고찰 ....................... 9
1. 음향학적 고찰 ................................................. 9
2. 계산 전략 ....................................................... 10
제2절 음향공의 음향학적 고찰 .................................. 11
1. 음향학적 고찰 ................................................. 11
2. 계산전략 ........................................................ 12
제 4 장 계산 및 결과 ................................................. 13
제1절 배플형 분사기의 음향학적 고찰 ....................... 13
1. 기본음향특성 ................................................... 13
2. 배플형 분사기가 장착된 연소실 응답 ......................... 15
3. 간극에 의한 감쇠효과 증대 메커니즘 분석 .................. 17
4. 배플의 길이변화에 따른 효과 ................................... 20
제2절 음향공이 장착된 연소실의 음향학적 고찰 .......... 24
1. 기음향공이 장착된 연소실 응답 ................................ 24
제3절 음향공이 장착된 연소실의 연소장 고찰 ............. 26
1. 연소장 계산의 이론적 고찰 ...................................... 26
2. 중간생성물을 고려한 순간화학반응 계산 .................... 29
3. 음속 및 동조주파수 계산 ......................................... 35

제 5 장 결론 ............................................................ 39

참 고 문 헌 ............................................................... 41
Degree
Master
Publisher
조선대학교
Citation
이중연. (2007). 로켓엔진 연소기의 연소안정화를 위한 수동제어기구 설계 기준 구축.
Type
Dissertation
URI
https://oak.chosun.ac.kr/handle/2020.oak/7072
http://chosun.dcollection.net/common/orgView/200000236049
Appears in Collections:
General Graduate School > 3. Theses(Master)
Authorize & License
  • AuthorizeOpen
  • Embargo2008-02-19
Files in This Item:

Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.