• International Journal of Aerospace System Engineering
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• 제3권1호
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• pp.25-29
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• 2016

This paper highlights the performance of an impulse turbine which is a part of turbopump in a liquid rocket first stage engine. The turbopump, currently under development at Korea Aerospace Research Institute, has an impulse type turbine with 12 nozzles and a single rotor. The impulse turbine can archive high specific power with the low gas flow rates. The supersonic impulse turbine with a single rotor can make a simple structure. High-pressure gases are converted into the dynamic energy with flows through the 12 nozzles and drive the rotor to make the power for the pumps. The turbine test was performed in the high-pressured turbine test facility with air gas instead of burned gas. A hydraulic dynamometer was used to absorb the power from the turbine and control the rotational speed and torque. The test points were at several pressure ratios with 7 different rotational speeds. Results showed the efficiency was highest at the design pressure ratio. The efficiency was insensitive to the pressure ratio variation than the rotational speed. It was a typical characteristic in an impulse turbine.

• 한국추진공학회지
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• 제18권1호
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• pp.42-49
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• 2014

설계성능이 검증된 70 N급 하이드라진 추력기에 대한 성능평가 시험이 수행되었다. 각각의 개발모델 추력기는 추력실 직경 변화에 따라 펄스모드로 연소시험이 수행되었으며, 비추력, 임펄스 비트 및 특성속도 등의 성능변수로 평가되었다. 추력실 직경의 증가와 감소에 따라 비추력과 특성속도가 감소하였으며, 성능평가 결과 표준모델의 성능특성이 가장 우수한 것으로 확인되었다.

• 한국추진공학회지
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• 제8권4호
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• pp.84-90
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• 2004

추진제 주입압력 350 psia 에서 0.95 lbf 의 정상상태 공칭추력을 내는 단일액체추진제 하이드라진 추력기의 성능평가 결과를 추력, 임펄스 비트, 비추력 등을 통하여 제시한다. 연소시험 형상과 절차에 대한 간략한 묘사와 더불어 정상상태 연소모드로부터 얻어지는 추진제 공급압력. 질량유량, 추력기 작동환경 진공도, 그리고 추력 등의 변이거동에 대한 전형적인 결과를 검토한다. 제시된 추력기 성능은 1-lbf급 표준형 단일추진제 로켓엔진의 기준성능에 성공적으로 비교된다. 선별된 추력기군을 위성체 추진시스템의 비행모델로 채택하기 위한 추력기간 성능편차에 대해 부연한다.

• 호남수학학술지
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• 제32권1호
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• pp.101-112
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• 2010

Using some interesting convolution, we find kernels recovering the given function f. By a slight change of this convolution, we obtain an identity filter related to the Fourier series in the discrete time domain. We also introduce some techniques to decompose an impulse into several dilated pieces in the discrete domain. The detail examples deal with specific constructions of those decompositions. Also we obtain localized moving averages from a decomposition of an impulse to make hybrid Bollinger bands, that might give various strategies for stock traders.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.219-222
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• 2007

본 연구에서는 노즐 외기 압력 변화에 따른 KSLV-I 2단 고체추진기관의 성능 분석을 수행하였다. 2단 고체추진기관은 고도 약 300km 상공에서 연소를 할 예정이다. 모터의 성능 검증을 위해 대기 압력 환경에서 연소시험을 수행하였다. 그리고, 환경 시험 설비를 적용하여 진공환경의 모터 성능 검증을 진행하였다. 지상 및 진공환경에서의 모터 비추력 변화를 통해 노즐 외기 압력이 고체추진기관의 성능에 미치는 영향을 분석하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.256-259
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• 2007

하이브리드 로켓의 원통형 multi-port 그레인에서 그레인 포트 개수 변화에 따른 연소특성을 고찰하였다. 후퇴율의 경우 그레인 포트 개수가 증가할수록 연료 포트 후퇴율과 끝단면 후퇴율 모두 증가하였다. 성능변수의 경우 그레인 포트 개수가 증가할수록 O/F 비는 낮아졌고, 비추력은 높아졌다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.328-331
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• 2008

A literature survey has been reported of the systems analysis on the liquid rocket engines. The analysis tools are mainly about the calculation of the rocket engine performance at the early days. However recent trend shows that researchers try to develop an integrated environment of distributed analysis tools for faster and cheaper analysis. This article presents the systems analysis results of the liquid rocket engine of gas generator cycle using the published mass estimating model. The specific impulse change for various thrust to weight ratio agrees qualitatively well with the published data.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.285-289
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• 2004

An optimal interplanetary trajectory is presented for Human Outer Planet Exploration (HOPE) by using an advanced magnetoplasma spacecraft. A detailed optimization approach is formulated to utilize Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine with capabilities of variable specific impulse, variable engine efficiency, and engine on-off control. To design a round-trip trajectory for the mission, the characteristics of the spacecraft and its trajectories are analyzed. It is mainly illustrated that 30 MW powered spacecraft can make the mission possible in five-year round trip constraint around year 2045. The trajectories obtained in this study can be used for formulating an overall concept for the mission.

• International Journal of Aerospace System Engineering
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• 제2권2호
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• pp.1-5
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• 2015

The powder propellant rocket which uses micron-sized particles as fuel is storable and costly. Functions like thrust control and multiple-ignition can be realized by changing powder mass flow rate. In this paper, we discuss the theoretical performance of bi-propellant and mono-propellant powder rocket. When used as the fluidization gas, helium can improve specific impulse dramatically. The stability of the powder feeding device is preliminarily quantified through metal/N2O powder rocket hot fire tests.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.235-242
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• 2008

An innovative Panel ExTension SATellite(PETSAT) and propulsion system for PETSAT, are presented in this paper. First, we outline what PETSAT is. Next, based on PETSAT ethos, design policy of the propulsion system is provided. According to the policy, we designed propulsion system and concretely estimated and assembled mono-propellant and bi-propellant systems, and it indicated that mono-propellant propulsion with 50-60 seconds of specific impulse and 1 N of thrust is probable. In the case of bi-propellant, 120-150 seconds of specific impulse is valid even based on the design policy. We conducted captive tests of mono-propellant and bi-propellant propulsions with a breadboard model of propulsion system for PETSAT, and obtained good operations and performances. Based on the test results, we designed and manufactured flight model propulsion system for PETSAT. We are planning to demonstrate it in SOHLA-2L project progressed by the Space Oriented Higashiosaka Leading Association(SOHLA). SOHLA-2L will be the first on-orbit demonstrator of PETSAT in 2008.