• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.29-37
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• 2015

This paper presents a numerical investigation on detonation of a kerosene-air mixture in the copper tube and the structural response associated with combustion instability in liquid rocket engine. A single step Arrehnius rate law and Johnson-Cook strength model are used to describe the chemical reaction of kerosene-air mixture detonation and the plastic deformation of the copper tube. The changes of flow field and tube stress which are induced by plastic deformation, are investigated on the different tube thicknesses and nozzle configurations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.25-28
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• 2010

The Cold flow and ignition tests have been performed for a technology demonstration model of 75-tonf liquid rocket engine thrust chamber which was designed and manufactured on the basis of the previous development experience of a 30-tonf liquid rocket engine thrust chamber. The hydrodynamic characteristics of the facility supply pipelines and the filling time of the cooling kerosene were obtained through the cold flow tests. The ignition cyclogram was determinded using the results and the ignition test was successfully carried out. The acquired data and test technique of present ignition test will be used in hot firing tests.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.95-98
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• 2010

A multi-injector rocket engine using high concentrated hydrogen peroxide and kerosene as the oxidizer and fuel was designed and fabricated. Six coaxial swirl injectors were mounted on the mixing head and flow analysis in the manifold was performed to minimize stagnation and recirculation zones. Finally, uniformity of mass flow rate and spray pattern was evaluated by cold flow tests and the mixing head design process was successfully verified the results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.81-84
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• 2010

In this study, a coaxial swirl injector using hydrogen peroxide and kerosene was designed and combustion performance tests were performed to evaluate combustion characteristic according to mixture ratio. Spray characteristic of the injector was verified by cold flow test and combustion performances according to mixture ratio were evaluated by the characteristic exhaust velocity. Test results showed that the combustion efficiency at the design condition was about 95% and the pressure fluctuation was very small.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.814-819
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• 2017

The objective of this paper is to observe effects of an ignition position and time on the ignition transition. A gaseous oxygen and liquid kerosene are used for propellants with the shear-coaxial injector. In order to study the ignition delay time and combustion instability intensity, the pressure transducer was used. The ignition position was changed with the injector spacer. Sequences except the igniter operation time were fixed to compare the ignition time only. Initial pressure peak and ignition delay time increased as the ignition time was delayed. Also, the unstable flame development zone was detected as the igniter was away from the injector.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.304-309
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• 2017

This paper studies a nonpremixed turbulent flame in a model scramjet combustor using zonal hybrid RANS/LES method. The numerical domain is divided into two region, RANS and LES region. The interface between the two regions is treated with synthetic eddy method. A model scramjet combustor experimented at German aerospace center is selected for the comparative study. The fuel injection of cracked kerosene surrogate which is composed of ethylene and methane is considered. Turbulent combustion of cracked kerosene surrogate is achieved using flamelet approach.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.31-34
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• 2012

Numerical simulations of the steady and unsteady state were conducted for a coaxial swirl injector with Kerosene fuel. Non-premixed equilibrium model based on chemical equilibrium assumption was used as turbulence-chemistry interaction model. As an equations of state, SRK(Soave-Redlich-Kwong) EOS was applied to deal with the behavior of real fluid in a high pressure condition. Through the steady and unsteady computations, mean values of steady and time-averaged unsteady state were compared on the temperature and OH mass fraction and it was shown that the flame structure of steady state was different to that of time-averaged unsteady state.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.103-108
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• 2011

The turbulent mixing of a kerosene/liquid oxygen coaxial swirl injector under supercritical pressures have been numerically investigated. Kerosene surrogate models are proposed for the kerosene thermodynamic properties. Turbulent numerical model is based on LES(Large Eddy Simulation) with real-fluid transport and thermodynamics over the entire pressure range; Soave modification of Redlich-Kwong equation of state, Chung's model for viscosity/conductivity, and Fuller's theorem for diffusivity to take account Takahashi's compressible effect. The effect of operating pressure on thermodynamic properties and mixing dynamics inside an injector and a combustion chamber are investigated. Power spectral densities of pressure fluctuations in the injector under various chamber pressure are analyzed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.89-92
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• 2011

The modeling of thermodynamic non-idealities and transport anomalies is a crucial prerequisite to realistically simulate the mixing and combustion processes of liquid propellants injected above critical pressures. This study has developed a specific set of subroutines to calculate the thermodynamic and transport properties based on the generalized cubic equation of state (EoS) in a coupled manner with the standard chemical kinetics packages (Chemkin). The existing flamelet analysis code is extended with the real-fluid package and applied to numerical investigation of local flame structures of kerosene and liquid oxygen at high pressure conditions relevant to the actual rocket engines.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.1
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• pp.72-79
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• 2018

An experimental study was performed to investigate the chemiluminescence characteristics in the spray combustion of ultransonically atomized kerosene. The radical intensity of the spray flame was measured using an ICCD camera and the amount of fuel consumed was obtained by a precise flow-rate measurement technique during combustion. Fuel consumption increased linearly with the increase in carrier-gas flow rate, and typical group combustion, which is a characteristic of spray combustion, was observed. It was found from the analysis of chemiluminescence that the maximum emission intensities of OH and CH radicals decrease, and they move downstream resulting in the increase in a vivid reaction zone as the spray flow rate increases.