• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.4
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• pp.53-62
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• 2003

A supersonic ground test facility to develop Ramjet and SCRamjet(Supersonic Combustion Ramjet) engine should be able to simulate high altitude and high Mach number conditions including air total pressure, oxygen level and specific heat ratio at the combustion chamber entrance. The test facility also should simulate the effect of oblique shock wave caused by the flight vehicle. The test facility developed in this study is supersonic free-jet blow down type, which consists of high pressure air supply source(maximum pressure=32MPa), air heater(vitiation type), supersonic diffuser, ejector, and test chamber(nozzle exit dimension=200mm${\times}$200mm).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.395-399
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• 2009

Advanced afterburner used in the most modernized gas turbine has new designing paradigm to cope with reinforced power density. The most distinct change is the designing trend to integrate fuel injectors and flame holder in order to manage higher temperature of inlet air. F414 and F110-GE-132 engine adopted this methodology and installed a variable nozzle utilizing CMC(Ceramic Matric Composite) material and active cooling of nozzle flap with ejector nozzle in order to enhance the life cycle of engine components and an economical aspect. These technological trends can be utilized for an advanced ramjet engine and combined cycle engine like TBCC.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.6
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• pp.10-18
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• 2015

Performance requirement analysis and weight estimation of a reusable launch vehicle with a rocket-based air-breathing engine(RBCC : Rocket Based Combined Cycle) were performed. Performance model for an RBCC engine was developed and integrated with flight trajectory model. The integrated engine-trajectory model was validated by comparing the results with those from previous research reference. Based on the new engine-trajectory model and previous research results, engine performance requirements were derived for an reusable launching vehicle with gross take-off weight of 15 tones. Dependence of the propellant amount requirement on the mode transition Mach number of the engine was also analyzed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.10
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• pp.61-70
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• 2006

A Supersonic air intake model was designed for the high performance ramjet and dual-mode scramjet engine to operate at Mach 4 flight condition. The air intake was tested in the blowdown-type wind tunnel of Kyushu University to identify the internal flow characteristics corresponding to the flight parameters such as the back pressure, angle of attack and angle of yaw. Flow visualization was achieved by the Schlieren and oil flow visualization techniques. The intake performance was analyzed quantitatively based on the surface pressure and total Pressure measurements. The experimental results were compared with the computational fluid dynamics results. The present study exhibits the fundamental but rarely found experimental results of the high Mach number supersonic air intake.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.73-80
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• 2018

At the early stages of development of high-speed propulsion systems, associated uncertainties cannot be easily modeled into probabilistic distributions, owing to the lack of test data, cost, and difficulty of simulating real-flight environments on the ground. To tackle this issue, in this research, the combustion efficiencies of dual-combustion ramjet engines are assumed to have been provided by experts and quantified by evidence theory. Using quantified uncertainty, the inlet area and combustor exit are optimized while satisfying reliability margins of thrust and thermal choking. The result shows a reasonable design of the engine under uncertain circumstances.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.10a
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• pp.12-12
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• 1998

무기체계의 추진체로서 고체 로켓트 추진기관이 제작의 용이성, 구조의 간단성, 이에 따른 저렴한 제작비, 그리고 고 신뢰도 확보가능 등의 여러 장점으로 대부분의 현존 전술 유도무기에 채택되어 사용되어 오고 있으나 대응, 방어 무기체계의 빠른 발전으로 이에 따른 새로운 추진기관의 유도무기체제가 요구되고 있다. 램제트 기관은 공기흡입추진기관으로 상대적으로 높은 비추력(1000-2000s)과 추력 중량비(∼20)을 가지며, 이로 인해 기존의 로켓 엔진에 비해 4-5배의 성능을 낼 수 있으며, 초음속 장거리 비행에 적합하다며, 또한 높은 속도영역까지 운용가능하고 구조가 비교적 간단하다.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.3
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• pp.56-66
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• 2013

Weight reduction of the VTHL / TSTO type of the reusable launch vehicles using RBCC engines are investigated. To predict weight and thrust of the vehicles, equations of motion are analyzed. Analysis results are compared with specifications of existing launch vehicles for validations. For the mission of inserting 2.5 ton payload to 200 km circular orbit, the case A, which uses the RBCC engine in the 1st stage shows smaller weight than the case B, which uses the RBCC engine in the 2nd stage. The weight of the case A shows only 25.8% of a existing rocket launch vehicle's weight.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.2
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• pp.18-24
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• 1999

Liquid ramjet combustor is closely connected with complex phenomena due to a series of processes such as intake air, spray, mixing, and combustion. The present numerical experiments were peformed to investigate these flow characteristics for two and three dimensional liquid ramjet combustor. Grid system was made with three domains: intake region where air is supplied and fuel is injected, combustor and nozzle region, and exit atmosphere region. The numerical results showed that two and three dimensional flow patterns in recirculation region of combustor were significantly different each other and spray model was necessary to predict correctly the chemical reaction flow characteristics. Numerically examined for two different location of fuel injector, one is located on the bottom position of curved intake and the other is located on the top position. We found that bottom position of fuel injector is better than top position because fuel influx to the recirculation region which is need to sustain chemical reaction is more than the latter.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.43-46
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• 2006

Storage air heater(SAH) is a general purpose facility that is used to simulate the high altitude condition of supersonic ground test facility, thurst compensation test of rocket engine nozzle and gas turbine engine combustor test. SAH in KARI is built to simulate the total temperature of the supersonic ground test facility which has a wide flight envelope from altitude 0km, Mach 2 to altitude 25km, Mach 5 and operates up to 1300K, 3.5MPa. In this paper, we introduces the SAH in JAXA which is model of SAH in KARI and summarizes the design process and manufacture of ours.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.6
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• pp.21-31
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• 2017

In the present study, theoretical and numerical analyses have been carried out to investigate the detailed flow characteristics during the mode transition. The theoretical analysis rearranged the knowledge of gasdynamics and the previous studies, and the numerical analysis has conducted to solve the 2D unsteady compressible Navier-Stokes equations with a fully implicit finite volume scheme. To validate the numerical analysis, the experiment was compared with it. The total temperature at the inlet of isolator and the hydrogen fuel equivalent ratio were changed to investigate their effects on the mode transition phenomenon. As the results, the numerical analysis reproduced well the experiment qualitatively, the increment in the hydrogen fuel equivalent ratio induced the scram-mode to ram-mode transition which is discontinuous with a non-allowable region, and the variation in the total temperature changed the boundary of the mode transition.