• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.326-329
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• 2008

DARPA's hypersonic propulsion program VULCAN is aimed for development of Mach 4+ capable engine by combining current production turbofan engine such as F119 with CVC (Constant Volume Combustion) engine. Final goal is a TBCC(Turbo-based Combined Cycle) engine by combining with dual mode ramjet/scramjet engine. CVC is a common designation of new concept of high efficiency engines, such as Pulse Detonation Engine (PDE) or Continuous Detonation Engine (CDE), which use the detonation as a combustion mechanism. Present paper introduces the internationally collaborative research activities carried out in Aerospace Combustion and Propulsion Laboratory of the department of Aerospace Engineering of the Pusan national University.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.394-398
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• 2005

Ramjet engine have been usually operated on Mach $1.5\sim3$ as the vehicle of supersonic cruising engine and studied about the higher performance above Mach 4. The research of Duel mode Scramjet engine which have duel operating mode of ramjet/Scramjet are in progress actively nowadays. This paper suggests the effect the flow characteristics and the effects of back pressure, angle of attack, angle of yow on the supersonic air intake on mach 4 through the Schlieren/Oil flow visualization, and pressure measurement on experimental model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.586-595
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• 2010

An analytical study based on physical understandings and aero-thermodynamic theories was conducted to observe the performance characteristics and to derive the essential design parameters of dual ramjet(dual-combustion/dual-mode) propulsion for wide Mach number. The performances and operating limitations of the engines with two types combustors, such as constant pressure- and constant area- combustor, over various flight Mach numbers was investigated. Finally, the transition Mach number from ramjet to scramjet was carried out to optimize performance load balancing of ramjet and scramjet.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.5
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• pp.90-98
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• 2016

A high temperature heater is required to supply high temperature air to the hypersonic propulsion system in order to simulate high velocity flying condition during the ground test. Various high temperature heaters were reviewed, categorized, and analyzed in this paper. Heaters were categorized in 4 groups; in-stream combustion heater, electric arc heater, storage heater, and heat exchange heater. Each group has its own advantages and disadvantages, so the heater should be selected considering its purpose.

• 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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.330-335
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• 2017

Recently many studies have been made for the development of propulsion system with wide range flight from supersonic to hypersonic. Dual Mode scramjet engine as a hybrid cycle with advantage of ramjet and scramjet has one combustor. It works under the ramjet mode (subsonic combustion) and scramjet mode (supersonic combustion) respectively. In this study, Experimental results of hot firing tests of dual scramjet engine designed on the condition of Mach 3.5~6 as a flight Mach number are discussed. The tests were carried out on a ground test bench under free stream condition of Mach 6 at 27.6km altitude. In the tests, the adopted design and technological solutions were verified and efficient operation of the dual mode ramjet engine with Kerosene combustion during 5 seconds was demonstrated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.136-140
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• 2005

By extending one-dimensional ZND detonation structure analysis model, a simple model for two-dimensional oblique detonation wave structure analysis is presented by coupling Rankine-Hugoniot relation and chemical kinetics for oblique shock wave and oblique detonation wave. Base on this study, two-dimensional fluid dynamics analysis is carried out to investigate the detailed unsteady structure of oblique detonation waves involving triple point, transverse waves and cellular structures. CFD results provide a deeper insight into the detailed structure of oblique detonation waves, and the simple model could be used as a unified design tool for hypersonic propulsion systems employing oblique detonation wave as combustion mechanism.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.303-306
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• 2008

After the successful flight test of X-43A, U.S. Airforce is developing missile-type X-51A SED (Scramjet Engine Demonstrator-Wave Rider). X-51A using PWR (Pratt and Whitney Rocketdyne) X-1 hydrocarbon fueled scramjet engine will have a ground test in 2008 and flight test in 2009. Technologies established though the X-51A program will be transferred to DARPA's Falcon program developing HTV (Hypersonic Test Vehicle)-3X and HCV (Hypersonic Cruise Vehicle). Present paper is an overview of propulsion core technologies of X-51 such as regenerative cooling of engine structures and combustion using liquid/supercritical JP-7 fuel.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.310-319
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• 2017

This paper introduces the method how to measure the thrust in impulse facility. In a Facility having such a short duration time of steady flow, there's no time to reach a steady state of the forces acting on model so that the test model vibrates until the end of the flow. The forces exerted on an engine exist with vibration so that the usual force balance can not be used. SWFB(Stress Wave Force Balance) technique is utilized in a shock tunnel to get the thrust. As an example, a model force balance has been calculated its strain against impulse force by using FEM(Finite Element Method). A transfer function between the impulse force and strain has been obtained by the way of de-convolution.

• 한국전산유체공학회:학술대회논문집
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• 1998.05a
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• pp.117-122
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• 1998

A numerical study is carried out to investigate the transient process of combustion phenomena associated with hypersonic propulsion devices. Reynolds averaged Navier-Stokes equations for reactive flows are used as governing equations with a detailed chemistry mechanism of hydrogen-air mixture and two-equation SST turbulence modeling. The governing equations are discretized by a high order accurate upwind scheme and solved in a fully coupled manner with a fully implicit time accurate method. At first, oscillating shock-induced combustion is analyzed and the comparison with experimental result gives the validity of present computational modeling. Secondly, the model ram accelerator experiment was simulated and the results show the detailed transient combustion mechanisms. Thirdly, the evolution of oblique detonation wave is simulated and the result shows transient and final steady state behavior at off-stability condition. Finally, shock wave/boundary layer interaction in combustible mixture is studied and the criterion of boundary layer flame and oblique detonation wave is identified.