• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.235-239
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• 2005

A 30-tonf-class fullscale thrust chamber for the application to a LEO SLV has been combustion tested over the wide ranges of a mixture ratio and a chamber pressure. The thrust chamber designed for an open cycle engine with a turbopump was tested with a ablative combustion chamber instead of a regenerative chamber to first evaluate its performance and function. The test results revealed stable combustion characteristics. The hardware survived the harsh environment and showed very sound functional characteristics. The estimated combustion efficiency of the chamber turned out to be 95% and a specific impulse at sea level was estimated as 254sec, which are comparable to or above the predicted design values.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.92-97
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• 2005

A series of combustion test was done to verify the optimization result of a gas generator for a 10 ton thrust liquid rocket engine. An injector element is F-O-F impinging type injector and the test was conducted with kerosene/LOX propellants. Test results of combustion temperature and pressure show a very good agreement with optimal design result and verify that the design method was properly established. And turbulence ring revealed its effectiveness in enhancing combustion gas mixing and temperature difference in the radial direction showed only less than 15K. Also turbulence ring induced only 3.2% pressure loss in the combustion chamber, which is far less than conventional level observed in a gas turbine engine. Axial temperature distribution also shows that turbulence ring could effectively reduce about 10% or more in gas generator length if its location is properly selected.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1050-1056
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• 2010

Diesel engines introduce only air into the cylinder, and the air is high lycompressed. Fuel is directly injected into the combustion chamber in high temperature and pressure. Therefore diesel engines have high thermal efficiency because of the high compression ratio, while having high level of particulate matter and nitrogen oxide emissions because of the direct fuel injection. Many technologies have been developed to reduce particulate matter and nitrogen oxide emissions from diesel engines. One of the technologies is hydrogen fuel introduced into the combustion chamber with diesel fuel. In this thesis tiny amount of hydrogen is supplied into the combustion chamber in order to enhance the combustion performance. The engine, in which hydrogen is introduced, is tested. There are 20 test conditions given as 5 torque values of 100%, 75%, 50%, 25%, 0%, and 4 engine speeds of 700rpm, 1000rpm, 1500rpm and 2000rpm for the two cases with or without hydrogen addition. Maximum torques and Idle torques at each engine speed are measured, then the torque values are divided into 4 levels with 25% increasing step. The result shows that the fuel consumption, smoke, CO are reduced while the NOx emission is slightly increased, and the hydrogen addition has not a great effect on the performance at low loads but a great effect at a maximum load.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.1-1
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• 2005

Japan Aerospace Exploration Agency(JAXA) has been conducting research and development of the Scramjet engines and their derivative combined cycle engines as hypersonic propulsion system for space access. Its history will be introduced first, and its recent advances, focusing on the engine performance progress, will follow. Finally, future plans for a flight test of scramjet and ground test of combined cycle engine will be introduced. Two types of test facilities for testing those hypersonic engines. namely, the 'Ramjet Engine Test Facility (RJTF)' and the 'High Enthalpy Shock Tunnel (HIEST)' were designed and fabricated during 1988 through 1996. These facilities can test engines under simulated flight Mach numbers up to 8 for the former, whereas beyond 8 for the latter, respectively. Several types of hydrogen-fueled scramjet engines have been designed, fabricated and tested under flight conditions of Mach 4, 6 and 8 in the RJTF since 1996. Initial test results showed that the thrust was insufficient because of occurrence of flow separation caused by combustion in the engines. These difficulty was later eliminated by boundary-layer bleeding and staged fuel injection. Their results were compared with theory to quantify achieved engine performances. The performances with regards to combustion, net thrust are discussed. We have reached the stage where positive net thrust can be attained for all the test coditions. Results of these engine tests will be discussed. We are also intensively attempting the improvement of thrust performance at high speed condition of Mach 8 to 15 in High Enthalpy Shock Tunnel (HIEST). Critical issues for this purposemay be air/fuel mixing enhancement, and temperature control of combustion gas to avoid thermal dissociation. To overcome these issues we developed the Hypermixier engine which applies stream-wise vortices for mixing enhancement, and the M12-engines which optimizes combustor entrance temperature. Moreover, we are going to conduct the flight experiment of the Hypermixer engine by utilizing flight test infrastructure (HyShot) provided by the University of Queensland in fall of 2005 for comparison with the HIEST result. The plan of the flight experiment is also presented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.313-317
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• 2005

The facility improvement for hot firing test of combustion chamber having thrust of 30-tonf class and chamber pressure of 60bara were performed at ReTF in KARI. The KSR-III main engine having combustion pressure of 13bara and thrust of 12.5tonf had been successfully tested in this facility. To increase the capability of the facility, the feeding and the trust measurement system have been modified. The modification of the feeding system plays also a role of ensuring the stability of propellant supply and two step ignition sequence of combustion chamber. The one-axis thrust measurement system of up to 60tons has been newly manufactured and installed in test stand and the water/kerosene supply lines with high pressure vessel of $4m^3$ and gas nitrogen vessel of $10m^3$ have been designed for regenerative cooling system. The results of cold flow test show that this facility has been successfully improved to satisfy the requirement for hot firing test of high performance combustor.

• Journal of the Korean Wood Science and Technology
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• v.51 no.5
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• pp.410-418
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• 2023

In this study, the combustion characteristics of the Tulip tree, which is the representative broad-leaved afforestation tree in Korea, were analyzed. The flame retardant performance of the Tulip tree was analyzed by analyzing combustion characteristics on a total of three test samples; flame retardant treated, both flame retardant and oil stain-treated, and untreated. Then the flame retardance grade was classified for each of them. According to the result, test samples showed the strongest flame retardance were in order of flame retardant treated (C), both flame retardant and oil stain-treated (B), and untreated (A). As a result of analyzing the total heat emission and maximum heat emission rates, which is the evaluation standard for interior materials of Korean domestic buildings, test samples with flame retardant treat or flame retardant and oil stain treat were qualified for the flame-retardant standard. Both flame retardant and oil stain-treated samples showed higher total heat release (THR) and heat release rate compared to flame retardant-treated samples as the oil causes combustion with oxygen. On the other hand, they didn't qualify the THR in Quasi-non-combustible standards. To determine the correlation between the physical and combustion characteristics of wood, the combustion characteristics of other diffuse porous wood species, with which the Tulip tree is affiliated were analyzed, and noticed that the characteristic correlates with the density and quantity of wood. The results of this study are expected to be used as basic information on the combustion characteristics of the Tulip tree.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.17-25
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• 2022

The pintle injector has many advantages in the key characteristics of a liquid rocket engine, such as combustion stability, combustion efficiency, and wide range of comprehensive thrust control, design and manufacture, and test fired under supercritical conditions. The pintle injector is manufactured with a rectangular, single-row orifice for thrust control and production considerations. In order to verify the combustion performance of the pintle injector and its potential as a commercial injector, the combustion characteristics were analyzed by varying the TMR (Total Momentum Ratio) and BF (Blockage Factor). The result of the hot firing test showed that the heat flux increased as TMR increased, and it confirmed that the characteristic velocity efficiency was more affected by BF than TMR. Suppose a single-row pintle injector with efficiency characteristics insensitive to changes in TMR can achieve high efficiency at low fuel differential pressure conditions. In that case, the variable pintle injector's design flexibility can be increase.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.739-745
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• 2017

Research of ADN-based monopropellant thruster is progressed by developed countries in Europe to replace toxic hydrazine, and ADN-based monopropellant thruster system is the only system that was proved in space environment. In this research, ADN-based propellant and catalyst was fabricated to develop ADN-based monopropellant thruster, and catalytic combustion performance with fabricated propellant and catalyst were evaluated with DSC-TG analysis. Catalytic combustion of propellant and catalyst was determined with firing test using 5 N scale liquid monopropellant thruster.

• Fire Science and Engineering
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• v.28 no.2
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• pp.48-53
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• 2014

In this study, we would evaluate fire risk by domestic standard for artificial turf installed on field and roofs. Today domestic regulation for artificial turf only applies to outdoor uses and especially KS M 3888-1 has compulsion but limited to school athletic facilities. Indoor regulation complying with National Emergency Management Agency (No. 2012-35) was enacted as recommendations. Thus this study did combustion test of artificial turf installed on field. Analyzed result by 45 degree flammability test, standard was inadequate to judge the fire risk so we compared and analysed its characteristic through combustion test of flame retardant finishing carpet used as flooring. Test and assessment result of its ignitionability by 45 degree flammability test showed that carpet was satisfied with flame retardant finishing performance standard contrary to artificial turf. For this reason, by conducting cone calorimeter test, the combustion property after ignition would be analyzed and evaluated and then this study will suggest a countermeasure for strengthening standard.

• 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.