• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.4
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• pp.123-130
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• 2000

Studies on the turbocharger itself or various aspects generated from turbocharged engine have been made on the performance for the natural aspirated engine equipped with the turbocharger and the intercooler. In this study, the performance prediction program based on turbocharger theory is developed for simulation which may reduced the cost and the trial -and-error time. The program is verified with the experimental results for 11, 000 cc diesel engine with the turbocharger and the intercooler . Also, various factors which are invisible in experiment are predicted using this program.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.74-78
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• 2010

Turbocharger in the application to a diesel engine was widely used in automobile industries for the improvement of engine performance. To comply with stringent emission standards, ball bearing turbocharger has been developed by applying new emission reduction technology. Up to date turbocharger has been proved as an essential part of diesel engines by demonstrating its improved engine performance, fuel efficiency and reduced emission as well. In this research, the performance of the ball bearing turbocharger was compared by the conventional journal bearing type turbocharger. The results shows that ball baring turbocharger was proved to be 10~13% higher fuel efficiency and 30% less average emission than journal bearing turbocharger.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.167-170
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• 2008

A TBCC(Turbine Based Combined Cycle) engine performance design method for reusable launch vehicles flying both in subsonic and supersonic regime was proposed. The TBCC consists of turbo jet engines and ramjet engines, operating individually or together according to operation schedule. The performance scheme of turbojet and ramjet was validated and the combined engine performance of the TBCC at a typical flight condition was analyzed.

• Advances in aircraft and spacecraft science
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• v.9 no.5
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• pp.401-414
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• 2022

In the present paper, the optimal selection of batteries for an electric pump-fed hybrid rocket engine is analyzed. A two-stage Mars Ascent Vehicle, suitable for the Mars Sample Return Mission, is considered as test case. A single engine is employed in the second stage, whereas the first stage uses a cluster of two engines. The initial mass of the launcher is equal to 500 kg and the same hybrid rocket engine is considered for both stages. Ragone plot-based correlations are embedded in the optimization process in order to chose the optimal values of specific energy and specific power, which minimize the battery mass ad hoc for the optimized engine design and ascent trajectory. Results show that a payload close to 100 kg is achievable considering the current commercial battery technology.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.2
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• pp.232-241
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• 2016

The turbocharger, to decrease the harmful exhaust gas(CO, HC and etc.) and $CO_2$ emission as well as the increase of the engine output, would be an useful method for engine downsizing. Therefore the thermal endurance of turbine blade, the lubrication of turbine shaft and the engine knock according to the supercharge of the inlet air, had been studied. And there had been much progress in these research tasks to be achieved a breakthrough. But a study on the built-in WGV of a gasoline engine for a passenger car which may effect on the engine performance, is few. In this paper, the effect of the embedded WGV on the engine performance was performed through the endurance test, which was conducted more than 300 hrs using the 4 stroke, 1998 cc, water-cooled engine. To sum up the major results, there were an abrasion in the area of the WGV head edge and the thermal deformation on the WGV head face, These phenomena led to reducing the boost pressure which caused the reduction in the volumetric efficiency of the engine. It resulted in decreasing the engine power gradually during the life cycle of the embedded WGV.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.281-286
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• 2001

The radial turbine has been successfully applied to the systems which request relatively small output compared with the axial turbine, and has low manufacturing cost due to it's small size and simple structure. Recently, the researches on the development and the efficiency maximization of the radial turbine are in progress corresponding with the trend toward miniaturization in turbo machinery and the development of small dispersed power generation systems. The radial turbine is to be applied to our turbo refrigerator of which engine speed is 26,000 rpm and turbine efficiency is $88\%$. Also, as a heat exchanger is accepted instead of a combustor in our turbo refrigerator, the design of radial turbine has been performed to be appropriate to the circumstance of low temperature air, not high temperature combustor gas, into the turbine inlet . This radial turbine is being developed in consideration with not only the aero-dynamic performance but also the simplification of manufacturing and integration, and the durability at operating condition. This paper refer to the performance evaluation about the radial turbine design by comparison with consulting from Russia and the our evaluation about various design factors which are considered in aero-dynamic design process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.2
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• pp.116-122
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• 2016

The performance characteristics of a TBCC engine considering the transition mode from a turbojet to a ramjet engine has been investigated. The performance of each engine was proposed and a transition mode of the TBCC engine has been evaluated by adjusting the operating rate of the ramjet engine and turbojet engine performance changes continuously. Based on the transition model, it was confirmed that the performance is continuously changed at various flight Mach numbers and altitudes. The performance characteristics including thrust and specific impulse considering various flight conditions and transition mode were analyzed, which testifies characteristics of the engine itself, as well as transition of the combined cycle.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.4
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• pp.102-108
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• 2004

A layout of regenerative liquid rocket engine using turbo pump has been designed for development of high performance liquid rocket engine. each components of engine system was placed by considering assembly and characteristic. first stage engine system is controled by one plane of axis gimballing and composed of four engine assembly to cluster with launch vehicle. second stage engine system is controled by two plane of axis gimballing and composed of one engine assembly. assembly and disassembly Processes and required program have been developed. various shape of instruments were also developed for carrying out assembly and disassembly process efficiently.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.211-212
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• 2008

• The KSFM Journal of Fluid Machinery
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• v.3 no.4 s.9
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• pp.38-43
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• 2000

Recently, KARI(Korea Aerospace Research Institute, Korea) and CIAM(Central Institute of Aviation Motors, Russia) have made an effort in developing a centrifugal compressor for a small gas turbine engine as part of a collaboration program. This compressor has been designed as a sub-component for an axial-centrifugal compression system for a small turbo-shaft engine aiming adiabatic efficiency higher than 0.81. The geometrical design requirement imposes restrictions to have high inlet hub-to-tip ratio and inlet swirl flow. In this study, the compressor has been designed using the generalized experimental data established from those compressors having pressure ratio of 3.7 to 5. From this generalized empirical correlation, desirable values of design parameters could be obtained. Subsequently, quasi-3D and 3D viscous flow analyses have been performed to ensure the adopted methodology. It is expected that the centrifugal compressor provides total pressure ratio of 4.89, corrected mass flow-rate of 1.64kg/sec, and adiabatic efficiency of 0.815 with inlet hub-to-tip ratio of 0.641. These relatively high total pressure ratio and inlet hub-to-tip ratio are the main distinctive features in this design. Besides, one of the main features of this centrifugal compressor is the adoption of a double-row bladed diffuser to effectively decelerate the transonic flow leaving the impeller. The compressor has been manufactured and will be tested in the near future.