• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년 영문 학술대회
• /
• pp.506-510
• /
• 2008

Ramjets are capable of much higher specific impulse than liquid rocket engines for high speed flight in the atmosphere. Ramjets, however, cannot generate thrust at low flight speed. Therefore, an additional propulsion device to accelerate the ramjet vehicle to a supersonic speed is required. In this study, we propose a novel ramjet propulsion system with a $H_2O_2$/Kerosene rocket as the accelerator for initial stage. In order to test the feasibility of this concept, consecutive reactors was built; one for the decomposition of $H_2O_2$ and the other for kerosene combustion. Decomposed $H_2O_2$ jet was injected to combustor through converging nozzle from gas generator and over this hot oxygen jet, kerosene was injected by spay injector. Through the various test cases, hypergolic ignition test was carried out and steady combustion was achieved.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
• /
• pp.601-604
• /
• 2004

Precise position and attitude control of pico-satellite requires huge number of impulses of the order of 10$^{-6}$ Ns. MEMS solid rocket array is a promising propulsion system but the higher degree of miniaturization causes unreliable operation mainly due to quenching. In order to breakthrough this situation, a novel design of solid micro-rocket is proposed, which generates tiny impulses repetitively from a single rocket not from array. This unique micro-rocket is based on the utilization of quenching, which causes propellant reaction to sustain only in a small area. A test chip of a micro solid propellant tank and micro heater array is fabricated and ignition test is conducted. Obtained results show the feasibility of this concept and future direction of this quenching-based propulsion is discussed.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 춘계학술대회 논문집
• /
• pp.169-170
• /
• 2010

• 한국항공우주학회지
• /
• 제36권5호
• /
• pp.491-496
• /
• 2008

본 연구에서는 RBCC (Rocket Based Combined Cycle)엔진이나 기존 램제트 추진기관의 초기 추력 제공에 과산화수소 가스발생기를 이용하는 새로운 추진시스템을 제안하였고, 기초 연구 수행으로서 촉매 분해된 과산화수소 제트에 케로신을 분사하여 자연발화 및 연소 특성을 연구하였다. 과산화수소는 촉매 베드를 통하여 분해된 후 축소노즐을 통해 연소실로 분사됐으며 이 제트에 인젝터를 통하여 수직으로 케로신을 액상으로 분무하였다. 연소실내에서의 온도와 압력을 측정하여 점화를 확인하고 자연발화 특성을 조사하였다. 400°C의 연소실 온도와 연료와 산화제 혼합비 0.6이상에서 자연발화와 안정적인 연소가 가능하였다. 이 결과를 통하여 램제트의 새로운 초기 가속장치의 가능성을 확인할 수 있었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 추계학술대회 논문집
• /
• pp.411-412
• /
• 2010

• Journal of Advanced Marine Engineering and Technology
• /
• 제17권3호
• /
• pp.50-59
• /
• 1993

Usually ship is propelled by the conventional propeller. When the conventional propeller is used for ship's propulsion, reduction of propeller noise is big issue in some special vessel. In order to reduce the acoustic noise of the propeller, novel propulsion system named as MHD propulsion system has been studied among researchers. In this paper, thruster characteristic analysis and system analysis of MHD propulsion system have been carried out. Firstly basic experimental apparatus is designed, fabricated and installed and test is carried out. Test results are compared with numerical analysis. It is confirmed that test results agreed with numerical results satisfactorily.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2010년도 제35회 추계학술대회논문집
• /
• pp.199-204
• /
• 2010

The objective of this paper is to present new binder systems that can be applied in composite rocket propellants, to improve properties of these propellants not only for better performance, but also to reduce waste and pollution. These novel systems are based on the thermoplastic elastomer (TPE) binders, which consists of copolymers with the addition of a plasticizer, and additives. The effect of the novel TPE binder systems on the burning rate and mechanical properties of AP based propellants was studied. The results show that propellants based on the novel TPE binders have a better energy performance than today's workhorse hydroxyl terminated polybutadine/ammonium perchlorate propellant, exhibit a similar range of burning rate, possess appropriate mechanical properties, and exhibit good processing and aging characteristics at low cost.

• 한국정밀공학회지
• /
• 제33권7호
• /
• pp.571-577
• /
• 2016

In this paper, we propose a novel propulsion method for a Biomimetic underwater robot, which is a bio-inspired approach. The proposed propulsion method mimics the pectoral fins of a real fish. Pectoral fins of real fish are able to propel and change direction. We designed the propulsion mechanism of 1 D.O.F. that has two functions (propel and change direction). We named this propulsion system 'Flipper'. The proposed propulsion method can control forward, pitch and yaw motion using the Flipper. We made an experimental underwater robot system and verified the proposed propulsion method. We measured its maximum speed and turning motion using an experimental underwater robot system. We also analyzed the thrust force from the maximum speed, using the thrust equation. Experimental results showed that our propulsion method enabled the thrust system of the biomimetic robot.

• Journal of Electrical Engineering and Technology
• /
• 제12권6호
• /
• pp.2365-2377
• /
• 2017

This paper addresses two interrelated problems concerning the tracking control of pod propulsion unmanned surface vessel (USV), namely, the modeling of pod propulsion USV, and tracking controller design. First, based on MMG modeling theory, the model of pod propulsion USV is derived. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network approximation and adaptive method. Meanwhile, unlike some existing tracking methods for surface vessel whose control algorithms suffer from "explosion of complexity", a novel neural shunting model is introduced to solve the problem. Using a Lyapunov functional, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of pod propulsion USV is proved; second, the neural shunting model is used to solve the problem of "explosion of complexity", and this is a combination of knowledge in the field of biology and engineering; third, the developed controller is able to capture the uncertainties without the exact information of hydrodynamic damping structure and the sea disturbances. Numerical examples have been given to illustrate the performance and effectiveness of the proposed scheme.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2006년도 제26회 춘계학술대회논문집
• /
• pp.229-232
• /
• 2006

Tetrahydrofuran(THF)과 Ethylene oxide(EO) 또는 EO를 단량체로 하여 양이온 개환중합을 이용한 새로운 합성방법으로 random 또는 tri-block HTPE(Hydroxyl-terminated polyether)를 합성할 수 있었다. 합성된 random과 tri-block HTPE를 IPDI/N-100혼합 디이소시아네이트 경화제와 촉매로 TPB(triphenylbismuth)를 사용하여 폴리우레탄을 제조하였으며, 혼합 이소시아네이트 화합물의 비율에 따른 폴리우레탄의 기계적 특성을 연구하였다. 그리고 폴리 우레탄 추진제 바인더 제조를 위한 prepolymer인 합성된 HTPE의 최적 경화 조건을 찾기 위해 HTPE의 후처리 과정, 우레탄 합성시 사용되는 촉매의 양 등의 영향에 대해 알아보았다.