• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.88-94
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• 2012

Development trend of modern HSDI diesel engine is now focusing on low fuel consumption and emission because of strong interest in global environmental protection. Two big branches of criteria for modern diesel engine development are down sizing and down speeding. Down sizing keeps engine operation condition to the direction of higher load and thus pursuing for better thermal efficiency. But this may cause degraded vehicle dynamic performance because of reduced back up torque. Down speeding keeps engine operation condition to the direction of slightly higher load and lower engine speed. Therefore reduction of back up torque can be limited within flat torque area. This study analyzed fuel economy effect of down speeding on a vehicle powered by HSDI diesel engine in aspect of engine friction work, intake and exhaust pumping work, exhaust hat loss and thermal loss of fuel leakage of fuel injection system. Contribution factor of each engine and vehicle related parameters under basic and down speeding condition were compared and work balance of down speeding during NEDC was analyzed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.173-181
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• 2008

Gas turbine engine for aircraft are usually operated at the altitude condition which is quite different from the ground condition. In order to measure the precise performance data at the altitude condition, the engine should be tested at the altitude condition by a real flight test or an altitude simulation test with an altitude test facility. In this paper describes the design of altitude test facility for turbo shaft engine. This facility will be located in test cell #2 at the Korea Aerospace Research Institute. Test Cell #2 will be used for altitude testing engines with mass flow rate up to 40kg/s and inlet temperatures in the range from $-65^{\circ}C$ to $200^{\circ}C$. The existing compressor/exhauster station with heater & cooler system will be used to simulate altitude conditions in Test Cell #2.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.416-424
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• 2016

A robust design of head gasket is pursued by using FEA model of engine assembly. Engine assembly model consists of cylinder head, block, gasket, and head bolt is constructed to understand a complex behavior of this engine compound. Thermal loading is performed on the assembled engine cylinder and block to obtain temperature field. Firing load is added to the results of heat transfer analysis to simulate the engine operation condition. Temperature filed results from heat transfer analysis are mapped into the structural mesh. Contact pressure distribution along the bead has been monitored for the engine operation condition. Based on the results obtained from the analysis, Taguchi method has been adopted for a robust design process of head gasket. Among the control factors, bolt size affects most robustness of head gasket sealing.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.9
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• pp.724-732
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• 1989

The structure of engine and its interaction are investigated and the construction of mathematical model for the performance evaluation is presented and then simulated. The total system is classified as air-fuel inlet element, intake manifold, combustion, and engine dynamics and their control function are schematically evaluated. Because of the model structure with general engine function and computer simulation of the chosen engine, physical characteristics of the corresponding engine and the engine data of normal operation state are used. According to the study, it is possible to predict the mixture rate by by the difference in the mass of fuel and air into cylinder and to evaluate and trace dynamic characteristic of operation state under various operating condition. The model characteristic under the transient operating condition makes it possible to effectively evaluate the operation of actual engine through the result of simulation.

• Tribology and Lubricants
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• v.13 no.2
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• pp.82-88
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• 1997

This paper describes an empirical equation which can be used to predict the engine condition of supersonic aircraft. The equation, which is derived from the trend analysis of JOAP data, represents the concentration of Fe particles in the engine oil. The result of the trend analysis shows that the concentration of Fe particles is a function of running time of engine oil. Meanwhile the slope of Fe concentration is a function of running time of engine. Threfore, the empirical equation was derived as $w=a(t_e).t_o+b$. However, the equation could not enough to diagnose the damaged part of engine quantitatively. To make up for the weak points of the equation, qualitative analysis was carried out. For that purpose wear debris were collected from the abnormal engine and analyzed by EDS to detect the damaged parts of engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.3
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• pp.210-219
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• 2014

The MPI dual injection engine can enhance the fuel efficiency and engine power. By using one injector per one intake port, MPI dual injection engine has an excellent fuel atomization and targeting injection. As the basic research for the MPI Dual injection engine design, this research was investigated in order to understand the characteristic of the in-cylinder flow and fuel behavior according to engine temperature condition and the fuel type in the MPI dual injection engines. The 3D unsteady CFD simulation for the MPI Dual injection engine was performed using STAR-CD. The engine operating condition was 2,000 rpm/WOT. The parameters for this study were fuel types, fuel temperatures and wall temperatures. As a result, the intake air amount, evaporated fuel in the cylinder and the fuel film on the wall were presented according to parameters that depend on the fuel properties and engine wall temperature. Also, the results were influenced by in-cylinder flow such as the intake flow, back flow and so on.

• Journal of Power System Engineering
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• v.13 no.1
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• pp.53-58
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• 2009

The emergency diesel generator(EDG) of the nuclear power plant is designed to supply the power to the nuclear reactor on Station Black Out(SBO) condition. The operation reliability of onsite emergency diesel generator should be ensured by a conditioning monitoring system designed to monitor and analysis the condition of diesel generator. For this purpose, we have developing the technologies of condition monitoring for the wolsong unit 3&4 standby diesel generator including diesel engine performance. In this paper, technologies of condition monitoring for the wolsong standby diesel generator are described about three step. First is for selection of operating parameter for monitoring. Second is for technologies of online condition monitoring, Third is for monitoring of engine performance.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.4
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• pp.104-111
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• 2005

Gas turbine engines for aircraft are usually operated at the altitude condition which is quite different from the ground condition. In order to measure the precise performance data at the altitude condition, the engine should be tested at the altitude condition by a real flight test or an altitude simulation test with an altitude test facility. In this paper, the present state of the altitude test facility and the test technologies at urn(Korea Aerospace Research Institute) will be introduced.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.17-23
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• 1999

This paper presents the characteristics of the gas flow in the engine cylinder under various intake flow conditins. The particle tracking velovimetry(PTV) was used to anlayze the gas flow pattern and flow field in the cylinder. Effects of tumble intensifying valve(TIV), swirl intensifying valve(SIV) and one-valve deactivated condition on in-cylinder flow patterns were compared with the baseline engine udner 600rpm motoring condition. In addtion, tumbel ration was estimated rwith results of in -cylinder flow fields. Base on experimental results, the tumble ration of in-cylinder flow field has the maximum value at the bottom dead center for the different four inlet conditions. In TIV condition, the tumble ration is 1.35 times larger than that of baseline engine and 1 intake valve deactivated condition is effective to improve in-cylinder swirl motion.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.460-468
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• 2008

Recent activities on the scramjet and rocket-ramjet combined-cycle engine of Japan Aerospace Exploration Agency(JAXA) are herein presented. The scramjet engines and combined-cycle engines have been studied in the world and JAXA has also studied such the engines experimentally, numerically and conceptually. Based on the studies, 2 to 3 m long, hydrogen-fueled engine models were designed and tested at the Ramjet Engine Test Facility(RJTF) and the High Enthalpy Shock Tunnel(HIEST). A scramjet engine model was tested in Mach 10 to 14 flight condition at HIEST. A 3 m long scramjet engine model was designed to reduce a dissociation energy loss in a high temperature condition. Drag reduction by a tangential injection and two ways of a transverse fuel injection were examined. Combustor model tests at three operating modes of the combined-cycle engine were conducted, demonstrating the combustor operation and producing data for the engine design at each mode. Aerodynamic engine model tests were conducted in a transonic wind tunnel, demonstrating the engine operation in the ejector-jet mode. A 3 m long combined-cycle engine model has been tested in the ejector-jet mode and the ramjet mode since March 2007. Carbon composite material was examined for application to the engines. Production of the cooling channel on a nickel alloy plate succeeded by the electro-chemical etching.