• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.657-662
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• 1996

Venting capability to prevent excess pressurization caused by loss of Residual Heat Removal System (RHRS) during mid-loop operation hat been evaluated analytically and the peak Reactor Coolant System (RCS) pressure was compared with the results of the MIDLOOP computer code. Even though analytical method if relatively simple, the results are in a good agreement with those of the computer code. For both methods, the peak pressures have not, exceeded the nozzle dam design pressure, if the vent paths such as pressurizer safety valves or a pressurizer manway are available in a closed RCS configuration with the nozzle dam installed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.91-91
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• 2009

Piezoelectric micro-pump should contain the physical running parts like check valves for acquiring the unilateral motion of fluid from the alternating motion of actuators. But the check valves raise many problems such as abrasion or exhaustive destruction by the recursive mechanical displacement To solve these problems, we propose a novle type piezoelectric valveless micro-pump using peristaltic motion due to the traveling wave excitation. Proposed pump model is consisted of two piezoelectric ceramic plates, elastic metal body, caps for covering flow path, rubber rings for sealing tightly and disk springs for the pressurization of pump body.

• 한국군사과학기술학회지
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• 제10권1호
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• pp.144-149
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• 2007

Behaviour of a thread joint of a rocket motor case show complex structural characteristics. Pre-torque must be applied to the threads to prevent the loosening of the interface from the additional pressure load. During the pressurization of the rocket motor case, the jointing face may be opened if the pre-torque were not set properly or the structure may be failed if the local concentrated stress exceeds the strength of the material. In this paper, the structural behaviour of a thread joint of a rocket motor case were analyzed by the finite element method and the results were compared to the experimental ones. A method to set a pre-torque for a thread joint were proposed to ensure the structural safety.

• 환경위생공학
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• 제14권4호
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• pp.165-171
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• 1999

A study on the synthesis of zeolite 4A using the bituminous coal fly ash from power plant was carried out. This study aims to investigate possibility for detergent builder with synthesized zeolite. It was examined at the crystallization conditions of atmospheric pressure and that of pressurization. The synthesized zeolite was proved to be Zeolite 4A type by means of the XRD and SEM analysis, and then the synthesized zeolite was used as an absorbent the remove the $Ca^{2+}$ ions in the water. In this study, commercial zeolite and synthesized zeolite reached equilibrium within 10 and 30 minutes respectively. The amount of $Ca^{2+}$ ions exchanged by the commercial zeolite, atmospheric pressure zeolite (zeolite A) and pressurized zeolite(zeolite PA) were 391mg/L(as $CaCO_3$), 323mg/L(as $CaCO_3$) and 355mg/L(as $CaCO_3$) respectively.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.111-114
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• 2008

본 연구에서는 과산화수소 분해 반응을 이용한 초소형 추력기 성능평가를 실시하였다. 물리 화학적 안정성이 뛰어나고 분해 성능이 좋은 백금을 촉매로 사용하고 세라믹 폼을 지지체로 선정하였다. 실험에 사용된 단일 추진제는 90wt% 과산화수소로 질소 가스를 통한 직접 가압 방식으로 추력기에 공급된다. 추력기의 성능을 평가하기 위해서 특성 속도 효율을 구하고 압력곡선을 통해서 압력 상승 시간, 압력 하강 시간, 반응 지연 등을 종합적으로 살펴본다.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.551-554
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• 2006

Inhibition of propellant temperature rising in liquid propulsion rocket using cryogenic fluid as a propellant is very important. Especially propellant temperature rising during stand-by after filling and pre-pressurization can bring into cavitation in turbo-pump. One of the method preventing propellant temperature rising in cryogenic feeding system is recirculating propellant through the loop composed of propellant tank, feed pipe, and recirculation pipe. The circulation of propellant is promoted through gas-lift effect by gas injection to lower position of recirculation pipe. In this experiment liquid oxygen and gas helium is used as propellant and injection gas. Under atmospheric and pressurized tank ullage condition, helium injection flow-rate is varied to observe the variation of recirculating flow-rate and propellant temperature in the feed pipe. There is appropriate helium injection flow-rate for gas-lift recirculation system.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.241-244
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• 2006

The analysis of propellant feeding sub-system is performed using a commercial code SINDA/FLUINT, the comprehensive finite-difference, one-dimensional, lumped parameter tool. With the code, cryogenic helium supply system, liquid oxygen supply system, helium injection cooling system are evaluated. The code gave satisfactory estimation scheme for propulsion system characterized by cryogenic temperature and high pressure, two phase flow. This paper focuses on presenting calculation scheme of propulsion sub-system using one-dimensional code like SINDA/FLUINT.

• 항공우주기술
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• 제3권2호
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• pp.116-123
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• 2004

KSlV-I 추진기관 공급계의 세부 해석을 통하여 각 부품별 요구조건을 설정하였다. 해석에는 범용 열유체 해석 프로그램인 SINDA/FLUINT를 활용하였다. 열전달 모델과 유동 모델을 적용함으로서 해석의 신뢰성을 높였으며 각 부품에 대한 운용 조건을 설정하였다. 본 해석을 통하여 SRR(System Requirement Review)에서 제시된 각 부분별 요구조건을 검토하였으며, 부품 선정을 위한 기본 자료로 활용할 수 있었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.248-251
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• 2007

블로우다운 산화제 공급 방식은 부품 수가 적어 신뢰도가 높고, 별도의 가압 탱크가 존재하지 않아 발사체의 총 중량을 감소시킨다는 측면에서 효과적이지만, 일정한 추력 성능을 보장하지 않는 단점을 내재하고 있다. 따라서 본 연구에서는 각 부품의 수학적 모델링을 통해 블로우다운 산화제 공급방식 하이브리드 로켓의 성능 해석 모델을 제안하여, 고유의 성능 특성에 대하여 고찰하였다.

• 한국산업융합학회 논문집
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• 제19권3호
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• pp.125-132
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• 2016

The swash-type piston pump is a device that discharges as much volume of hydraulic oil generated as it moves the ramp by controlling the angle of the swash. This pump is suitable for high-speed high pressurization, and due to its useful characteristic being the variable capacity-type, it is used as a main pump for heavy equipment in various fields such as defense, shipbuilding, construction, etc. This study intends to obtain optimal design values by conducting a structural analysis in order to verify its reliability during the design process of the newly developed swash-type piston pump.