• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
• /
• pp.1-2
• /
• 2012

Active process of industrialization of near-earth space assumes design and development of high effective propulsion systems with a small thrust. The specific place among propulsion systems with a small thrust is taken the propulsion systems with use of electrical propulsion thrusters (EPT).

• 센서학회지
• /
• 제33권4호
• /
• pp.216-223
• /
• 2024

Electric propulsion systems, including electrothermal, electrostatic, and electromagnetic thrusters, are promising systems for producing thrust from satellites. These systems generally operate under vacuum plasma conditions and exhibit high specific impulses and thrust-to-weight ratios. Despite their high efficiencies, electric propulsion systems are susceptible to performance variations due to physical factors such as plasma instabilities, which require an accurate diagnosis of their status during operation. In this study, we review various measurement systems adopted to diagnose electric propulsion systems operating under vacuum conditions. Specifically, we review electrical, optical, and other methods that can directly or indirectly measure the status of a thruster, with a particular focus on Hall effect thrusters. The system configurations and fundamental mechanisms of the different measurement systems are described based on case studies of the diagnosis of propulsion systems. We anticipate that this study will contribute to the efficient development and safe operation of electric propulsion systems for use in artificial satellites.

• 한국군사과학기술학회지
• /
• 제24권4호
• /
• pp.418-425
• /
• 2021

Submarines are weapons systems that have been proven to be useful in battle since World War I and have continued to improve the efficiency of propulsion systems in order to be used efficiently on the battlefield. In particular, countries that unable to utilize nuclear propulsion systems make efforts to increase the efficiency of Air Independent Propulsion systems, and typical examples are fuel cells, Stirling engines and MESMA. It is also expected that the development of new propulsion systems such as hydrogen-reformer fuel cells, metal-air fuel cell and direct combustion propulsion systems will continue, so the characteristics of these will be examined and the performance based on the published data be checked in this thesis.

• Advances in aircraft and spacecraft science
• /
• 제6권5호
• /
• pp.427-442
• /
• 2019

Small satellites represent an emerging opportunity to realize a wide range of space missions at lower cost and faster delivery, compared to traditional spacecraft. However, small platforms, such as CubeSats, shall increase their actual capabilities. Miniaturized electric propulsion systems can provide the satellite with the key capability of moving in space. The level of readiness of miniaturized electric propulsion systems is low although many concepts have been developed. The present research intends to build a flexible test platform for the assessment of selected small propulsion systems in relevant environment at laboratory level. Main goal of the research is to analyze the mechanical, electrical, magnetic, and chemical interactions of propulsion systems with the modern CubeSat-technology and to assess the performance of the integrated platform. The test platform is a 6U CubeSat hosting electric propulsion systems, providing mechanical, electrical and data interfaces, able to handle a variety of electric propulsion systems, thanks to the ability to regulate and distribute electric power, to exchange data according to several protocols, and to provide different mechanical layouts. The test platform is ready to start the first verification campaign. The paper describes the detailed design of the platform and the main results of the AIV activities.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년 영문 학술대회
• /
• pp.407-412
• /
• 2008

"KAGUYA"(SELENE) is a Japanese Lunar Explorer launched by H-IIA rocket from Tanegashima Space Center on 14 September 2007. The dual-mode bipropellant propulsion subsystem of KAGUYA includes two fuel tanks, an oxidizer tank, propellant and pressurant control components, twelve monopropellant 20N thrusters, eight monopropellant 1N thrusters, and a bipropellant 500N Orbit Maneuver Engine(OME). Once the KAGUYA separated from the rocket, it circled the Earth twice and traveled to the Moon, where it entered lunar orbit. All maneuvers were performed through multiple 500N OME/20N thruster firings. This paper describes the in-space performance of KAGUYA Lunar Explorer bipropellant propulsion subsystem.

• 항공우주시스템공학회지
• /
• 제2권1호
• /
• pp.37-45
• /
• 2008

KARI has jointly developed COMS bipropellant propulsion system with EADS Astrium, UK. It is well known at the moment about American or even German efforts for space development and space propulsion activities. On the contrary UK's capability for space development hasn't been recognised well in Korea. The major space activities relevant to the development of chemical and electric propulsion systems in UK, in reference to our space propulsion programme are addressed in detail. In addition the collaboration in prospect between two countries is proposed.

• Journal of Advanced Marine Engineering and Technology
• /
• 제24권1호
• /
• pp.18-24
• /
• 2000

As ship's propulsion shafting system has been complicated, many linear methods that have been used until now are not sufficient enough to produce proper solutions and these solutions are ofter unreasonable. So we need to solve nonlinear systems, and many methods for solving nonlinear vibration system have been developed. In this study, the propulsion shafting system was modeled with Duffing's nonlinear vibration system and multi-degree-of-freedom, and analyzed by using Quasi-Newton method. And for the purpose of confirming the reliability of the calculating results for nonlinear forced torsional vibration of the propulsion shafting system, the nonlinear calculated results were compared with the linear calculated ones for ship's propulsion shafting system. In the result, for analysis of the forced torsional vibration of the propulsion systems with nonlinear elements, the modified Newton's method is confirmed reasonable.

• 수산해양기술연구
• /
• 제50권1호
• /
• pp.75-82
• /
• 2014

In vibration analysis of ships, the principle aim is to determine the natural frequencies and excitation frequencies, and use this information to avoid resonances and vibration damage. The simplest method is to prevent resonance conditions, which is effective as long as the natural frequencies and excitation frequencies can be regarded as independent from environmental conditions. For ships that use electric propulsion systems, the sources of vibration are reduced compared with those caused by a diesel engine or other combustion-based propulsion systems. However, the frequency spectrum of these vibrations may be different; therefore, to understand the characteristics of the electric propulsion, we also should investigate how the ship responds to these vibrations. We focused on a 1,000-ton deadweight (DWT) ocean-research vessel using an electric propulsion system and analyzed the response to vibration.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
• /
• pp.227-230
• /
• 2004

The regulator that was designed for space use must be operating on the severe circumstance. For example, operating temperature is below 90K and operating pressure is 20.7 MPa. The design of regulator for liquid propulsion system was accomplished and dynamic characteristic was analyzed successfully.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
• /
• pp.167-174
• /
• 2011

고체추진기관은 구조가 비교적 간단하고 장기적 저장성이 우수한 반면에 일반적으로 추력의 조절 등에 한계성을 가지고 있다. 본 논문에서는 핀틀 밸브 등과 같은 특수한 노즐을 사용하는 가변추력 고체추진기관의 압력 및 추력 제어 알고리즘을 제안한다. 이를 위해 질량보존만을 고려한 추진기관의 연소기 내 압력변화 모델에 대하여 고전적인 비례-적분 제어기와 모델의 비선형성을 피드백을 통해 제거하고 이를 선형모델로 대치하는 피드백 선형화 제어기를 설계하고, 압력제어모델의 추력계산식을 얻어내어 추력제어모델을 제시한다. 운용점에 대해 선형화하여 비례-적분 제어기를 설계하고, 시뮬레이션을 통하여 모델의 성능을 분석한다.