• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.581-585
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• 2009

In this study, conceptual design of the RBCC (Rocket Based Combined Cycle) engine was performed for the hypersonic propulsion system development. For the flight mission, RBCC engine takes off at sea level and accelerates up to Mach 8 at the altitude of 30km. By the flight speed characteristics, operating pattern of the engine is categorized into 3 modes : Ejector jet (~Mach 3), Ramjet (Mach 3~6), Scramjet (Mach 6~8). According to the engine mode characteristics, RBCC engine design and analysis was performed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.460-468
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• 2008

Recent activities on the scramjet and rocket-ramjet combined-cycle engine of Japan Aerospace Exploration Agency(JAXA) are herein presented. The scramjet engines and combined-cycle engines have been studied in the world and JAXA has also studied such the engines experimentally, numerically and conceptually. Based on the studies, 2 to 3 m long, hydrogen-fueled engine models were designed and tested at the Ramjet Engine Test Facility(RJTF) and the High Enthalpy Shock Tunnel(HIEST). A scramjet engine model was tested in Mach 10 to 14 flight condition at HIEST. A 3 m long scramjet engine model was designed to reduce a dissociation energy loss in a high temperature condition. Drag reduction by a tangential injection and two ways of a transverse fuel injection were examined. Combustor model tests at three operating modes of the combined-cycle engine were conducted, demonstrating the combustor operation and producing data for the engine design at each mode. Aerodynamic engine model tests were conducted in a transonic wind tunnel, demonstrating the engine operation in the ejector-jet mode. A 3 m long combined-cycle engine model has been tested in the ejector-jet mode and the ramjet mode since March 2007. Carbon composite material was examined for application to the engines. Production of the cooling channel on a nickel alloy plate succeeded by the electro-chemical etching.

• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.111-119
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• 2013

Conceptual design of RBCC (Rocket Based Combined Cycle) engine is performed through the thermodynamic cycle analysis. The engine is designed to take off at sea level and accelerate to Mach 8 at 30 km altitude. According to the flight speed, the engine operating modes are categorized into 3 modes : Ejectorjet (~ Mach 3), Ramjet (Mach 3~6), Scramjet (Mach 6~8). As a design result, the engine has a diameter of 1 m and a length of 6.7 m. In the prediction results, its maximum thrust is 16.5 ton. In Ramjet and Scramjet modes, design condition of the engine intake influence the engine thrust according to the flight speed.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.6
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• pp.33-41
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• 2015

Scaled model of a dual-mode ramjet engine with large backward-facing step, as a component of the rocket-based combined cycle engine, was designed. Design parameters were derived for this engine with the consideration of application for the rocket-based combined cycle engine. Design methodology was established for these design parameters. The design was partially verified through numerical study. Flow characteristics of the dual-mode ramjet engine with large backward-facing step was investigated experimentally. The design methodology for relevant design parameters established in this study was verified as feasible.

• 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.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.4
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• pp.529-536
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• 2015

Various R&D programs for rocket-based combined cycle (RBCC) engines have progressed worldwide for the space development and the defense applications. As a way toward indigenous domestic RBCC program, a preliminary design of flight test conditions was studied in this study for a sub-scale RBCC engine using a sounding rocket. Launch and flight profiles were calculated for several booster options and compared with that of HyShot II program. The result shows that the Korea Sounding Rocket-II (KSR-II) is a proper candidate to perform the flight test available in Korea. The recommend flight test conditions with KSR-II are Mach 6.0 with a test vehicle of 230 kg and Mach 7.4 with 50 kg. Present study will soon be followed by a design of sub-scale RBCC for a flight test using a sounding rocket.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.122-129
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• 2008

Rocket Based Combined-Cycle(RBCC) engines are currently being explored as advanced propulsion for space transportation. JAXA has been conducting RBCC engine research by using various experimental facilities. In order to clarify the experimental results and contribute to the improvement of designing, the analysis of the RBCC engine in an ejector-jet mode was carried out using the CFD code developed in-house for unstructured grids. CFD replicated the characteristic flow structures. The numerical simulation of the pumping performance of the ejector driven by different rocket gases(He, $N_2,\;A_r$) and physical conditions were performed, and their effects on the performance were studied.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.6
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• pp.83-90
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• 2016

Ramjet mode combustion test was performed for a dual-mode ramjet engine model. The engine model consists of an air intake, a combustor and a nozzle. The combustor in the model has a large backward-facing step, designed to be used as a part of a rocket-based combined cycle engine. The test was performed at the flight speed of Mach 5 and the altitude of 24 km. Strong combustion was established only when the fuel was injected from both of the bottom-side and cowl-side wall. When the total fuel stoichiometric ratio was 1.0, distributed as 0.5 on the cowl side and 0.5 on the bottom side, the flow became subsonic at some portion in the combustor by thermal choking, i.e., ramjet mode was established for this condition.

• 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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.705-708
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• 2011

Ejector system can induce the secondary flow or affect the secondary chamber pressure by both shear stress and pressure drop which are generated in the primary jet boundary. Ejectors are widely used in a range of applications such as a turbine-based combined-cycle propulsion system and a high altitude test facility for rocket engine, pressure recovery system, desalination plant and ejector ramjet etc. The primary interest of this study is to set up an design procedure on the configuration and operating condition of multi-ejector for the various high altitude simulation.