• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.139-143
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• 2007

The overall results of combustion tests performed for a 30 tonf-class full-scale combustion chambers of a liquid rocket engine were described. The combustion chambers have chamber pressure of 53${\sim}$60 bar and propellant mass flow rate of 89 kg/so The combustion chamber is composed of mixing head, SUS baffle, baffle injector, ablative chamber, channel cooling chamber and regenerative cooling chamber. The test results show that the combustion characteristic velocity is in the range of 1673${\sim}$1730 m/sec and the specific impulse of the combustion chamber is in the range of 254${\sim}$263 sec. As the recess number of the injectors increases, the combustion characteristic velocity increases. And as the combustion characteristic velocity increases, the specific impulse of the combustion chamber also increases.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1905-1910
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• 2001

Pressure resonance frequency that is caused in the combustion chamber can be interpreted by acoustic analysis. Until now the pressure resonance has been assumed and calculated to a disc type combustion chamber that neglected the combustion chamber height because the knock occurs near the TDC(top dead center). In this research FEM(finite element method) has been used to calculate the pressure resonance frequency inside the experimental engine combustion. The error of the resonance frequency obtained by FEM has decreased about 50% compared to the calculation of Draper's equation. Due to the asymmetry in the shape of the combustion chamber that was neglected in Draper's equation we could find out that a new resonance frequency could be generated. To match the experimental results, the speed of sound that satisfies Draper's equation is selected 13% higher than the value for pent-roof type combustion chamber.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.71-75
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• 2009

Test results of combustion chamber to verify the operation and the combustion performance at low pressure, design and off-design conditions for 30ton-class liquid rocket engine were described. The combustion chamber has nominal chamber pressure of 60 bar, propellant mass flow rate of 89 kg/s, and nozzle expansion of 12. Effects of chamber pressure on combustion characteristic velocity are largely affected by mixture ratio. The specific impulse of combustion chamber is proportional to the chamber pressure regardless of the mixture ratios. The present results can be used as the base to predict the combustion performance of large sized chamber at high pressure while demonstrating the possibility of low pressure firing test of large sized chamber.

• Journal of the Korean Society of Combustion
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• v.2 no.1
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• pp.17-27
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• 1997

It is well known that NOx formation has a strong dependence on the maximum temperature and correspondingly with the maximum chamber pressure of a closed combustion system. However, in a case of impinging-jet-flame (IJF hereafter) combustion with opposed dual pre-chambers, low $NO_x$ formation with high pressure could be achieved, but its mechanism has not been clearly understood so far. In this study, a three-dimensional analysis is adopted to resolve time-variant local properties that might indicate the mechanism of IJF combustion. Numerical results are verified by comparing them with experiments. The IJF combustion in a vessel with no pre-chamber, with single pre-chamber, and with dual pre-chambers is studied. The orifice diameter and the volumetric ratio of pre-chamber are used as geometric parameters. The effects of main-chamber ignition delay time and combustion time of main-chamber, orifice exit velocity, orifice exit temperature, turbulent kinetic energy of main-chamber and spatial distribution of temperature in the latter stage of combustion are investigated. A longer main-chamber ignition delay and a shorter main-chamber combustion time suppress the formation of high temperature region with respect to mean temperature, which consequently results in less NO production.

• Journal of ILASS-Korea
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• v.1 no.3
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• pp.29-36
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• 1996

The present study systematically investigates the effect of evaporation rate on the combustion characteristics and the flame stabilization in a gasoline engine. A constant volume combustion chamber was used to elucidate a basic combustion characteristics and the premixer was installed to control temperature and equivalence ratio. And the maximum pressure, combustion duration and flame propagation according to the evaporation rate were measured to determine the optimal temperature range for evaparating a gasoline fuel. These experimental results indicate that the combustion characteristics such as combustion chamber pressure and combustion duration were deteriorated by decreasing surrounding temperature of fuel injected. It was also found that the overall gasification process for gasoline fuel was strongly influenced by a combustion chamber temperature rather than a premixer temperature.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.859-864
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• 2000

This paper reports a numerical flow characteristic analysis in gas boiler combustion chamber. The numerical results with simplification and assumptions were found within 30% of the experiment. A lot of geometrical modification has been invested in attempt to obtain the uniform flow in the combustion chamber exit. As a result, the velocity magnitude of the combustion chamber is relate with the hole size in air distribution plate. The velocity uniformity of the combustion chamber is relate with the number of holes and location in air distribution plate.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.4
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• pp.50-60
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• 1987

Combustion characteristics of opposed-jet-flames spouting out from dual prechambers of a divided combustion chamber were investigated by using high speed schilieren photography and chamber pressure measurement. Result shows that opposed-jet-flames are characterized by the parameter ( $A_{ori}$/ $V_{p}$) and there exists a certain critical value of ( $A_{ori}$/ $V_{p}$)c which distinguishes flame propagation patterns in the main chamber. Also higher chamber pressure and shorter total burning time can be derived by adopting this dual prechamber divided combustion chamber, which would lead a possibility of an appropriate combustion method of high load and low emissions.ons.ons.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.7
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• pp.1055-1062
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• 2004

As for the Production of internal combustion engines there has been further movement toward development of high Performance engines with improved fuel efficiency as well as a lightweight and a small size. These tendencies help to solve the problems in engines for example, such as thermal load. abnormal combustion and so on. In order to investigate these Problems, a thin film-type probe for measuring instantaneous temperature has been suggested. A method for manufacturing such a probe was established in this study The instantaneous surface temperature of a constant volume combustion chamber was measured by using this probe and the heat flux was obtained through Fourier analysis In order to thoroughly understand the characteristics of combustion. authors measured wall temperature of combustion chamber and calculated heat flux through a cylinder wall while varying the protrusion height of probe. For these Purposes, the instantaneous surface temperature probe was developed. thereby making possible the analysis of instantaneous temperature of wall surface and the detection of unsteady heat flux in the constant volume combustion chamber.

• Journal of Power System Engineering
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• v.2 no.2
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• pp.27-34
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• 1998

The purpose of this study is to investigate the performance of swirl combustion chamber diesel engine by changing the jet passage area and its angle, the depth and shape of the piston top cavity(main chamber). The performance of diesel engine with newly changed swirl combustion chamber was tested through the experimental conditions as engine speed, load and injection timing etc. The test results were compared and analyzed. The rate of fuel consumption was affected significantly by the jet passage area at the high speed and load, by the depth of the piston top cavity at the low speed and load. The exhaust smoke density and exhaust gas temperature depended sensitively on variation of the injection timing rather than the shape of the combustion chamber within the experimental conditions.

• Journal of Power System Engineering
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• v.1 no.1
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• pp.22-34
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• 1997

Circumstances require improving diesel engine, and many studies have been done in constant volume chamber(CVC). Because the combustion mechanism of a diesel engine has many difficulties with non-homogeneous nature, there has been a limitation to analyzing the combustion mechanism with CVC. Studies are often given in a real engine, but also it has difficulties in modifying configuration of combustion chamber etc. To get more easy way for mote engine-like test, a rapid compression mechanism has been introduced. This study addresses to designing a rapid compression expansion machine(RCEM) driven by compressed air, and to applying it on IDI diesel combustion chamber which has a glow plug. RCEM is introduced first and its characteristics are tested, then spray/combustion characteristics of diesel spray impinging on a glow plug in RCEM combustion chamber are investigated. The results show active combustion in the system employing spray impinging on a glow plug so as to improve combustion efficiency.