• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.517-524
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• 2005

An aerodynamic design for centrifugal compressor which was applied to medium speed diesel engine has done. First of all, exact compressor specifications must be defined by accurate engine system matching. This matching program has been developed. Using the mean1ine prediction method, geometric design and performance curve for compressor was done and verified by comparing three dimensional viscous CFD results. The deviation at the design point was about 2.3%. Combustor has been designed and manufactured for the performance test of medium speed diesel engine turbocharger. Fuel nozzle of combustor was designed and performed by PIV and PDPA test equipment. Through these results, spray characteristics were studied and flow coefficient equation was deduced.

• Journal of the korean Society of Automotive Engineers
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• v.10 no.6
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• pp.25-38
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• 1988

As a mean of increasing engine power, great attention has been concentrated on the turbo-charging owing to better fuel economy, smaller engine size and lower emission. The performance in turbocharged engine depends not only on the efficiency of the engine and the turbocharger used, but also on the total characteristics of the system by the matching turbocharger to the engine. The matching of the turbocharger to the engine has been usually accomplished by the empirical techniques with a great deal of laborious work. It would be better to predict the performance and emission in the turbocharged engine using the effective simulation model. In this study, computer simulation program has been developed to predict the transient variation of properties of gas in the cylinder, intake and exhaust pipes, the engine performances and emissions.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.44-48
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• 2008

This paper describes on studies of the heavy duty engine calibration for better fuel economy based on real driving conditions. Using testbed validated software simulation of the engine and turbocharger system, an alternative turbocharger specification, with potential to improve fuel economy was identified. Secondly, the engine calibration was modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the steady-state (testbed) emissions legislation. These results were confirmed by field testing of a vehicle equipped with the updated specifications. This study found good agreements between the prediction and the field test on the vehicle fuel economy improvements of the express bus with updated calibration and turbocharger.

• International Journal of Fluid Machinery and Systems
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• v.9 no.4
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• pp.332-337
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• 2016

Turbocompounding is a key technology to satisfy the future requirements of diesel engine's fuel economy and emission reduction. A turbocompound diesel engine was developed based on a conventional 11-Liter heavy-duty diesel engine. The turbocompound system includes a power turbine, which is installed downstream of a Variable Geometry Turbocharger (VGT) turbine. The impacts of the VGT rack position on the turbocompound engine performance were studied. An optimal VGT control strategy was determined. Experimental results show that the turbocompound engine using the optimal VGT control strategy achieves better performance than the original engine under all full load operation conditions. The averaged and maximum reductions of the brake specific fuel consumption (BSFC) are 3% and 8% respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.2
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• pp.190-197
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• 2003

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.880-885
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• 2007

Diesel engines have been widely used in ships and power plants because of its higher thermal efficiency, mobility and durability compared to other prime movers. Though these merits, diesel engine including main components are sometimes vibrated due to higher combustion pressure in cylinders. Especially torsional, axial and structural vibrations in propulsion shafting may be severely manifested by the malfunction of torsional and axial dampers and misfiring and unbalanced load in cylinder. The structural vibration of main body and turbocharger core hole are also occurred by the loosen top bracing and excess wear-out or failure of turbocharger's bearings. The marine diesel engine should be safely designed from these vibrations. This paper introduces experimental methods to develop the prototype of integrated vibration monitoring system for marine diesel engine.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.4745-4750
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• 2011

A HIL(hardware-in-the-loop) system was established and the simulation was carried out to determine whether the system operates normally. The system consists of turbocharger test bench, HIL platform with real time S/W and DAQ, and engine model using Matlab/Simulink. In the simulation the supplied fuel rate is changed step-by-step from 1.8944 kg/h to 4.7360 kg/h. The change of air-fuel ratio is analyzed and observed whether the air-fuel ratio follow the target air-fuel ratio 32. When the supplied fuel rate is changed, the air-fuel ratio is converged to the target air-fuel ratio after about 20 seconds. And the vane duty ratio of turbine and the boost pressure of compressor are also changed properly. Therefore this HIL system can be used to develop the new turbocharger and improve the performance of the modified turbocharger.

• The KSFM Journal of Fluid Machinery
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• v.9 no.2 s.35
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• pp.30-38
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• 2006

An aerodynamic design for centrifugal compressor which was applied to medium speed diesel engine has been done. First of all, exact compressor specifications must be defined by accurate engine system matching. This matching program has been developed. Using the meanline prediction method, geometric design and performance curves for compressor were established and verified by comparing three dimensional viscous CFD results. The deviation at the design point was about 2.3%. Combustor has been designed and manufactured for the performance test of medium speed diesel engine turbocharger. Fuel nozzle of combustor was designed and its characteristics was analyzed by PIV and PDPA test equipment. Through these results, spray characteristics were studied and flow coefficient equation was deduced.

• International Journal of Fluid Machinery and Systems
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• v.8 no.1
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• pp.23-35
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• 2015

This paper presents the rotordynamic performance measurement of oil-free turbocharger (TC) supported on gas foil bearings (GFBs) for 2 liter class diesel vehicles and comparison to floating ring bearings (FRBs). Oil-free TC was designed and developed via the rotordynamic analyses using dynamic force coefficients from GFB analyses. The rotordynamics and performance of the oil-free TC was measured up to 85 krpm while being driven by a diesel vehicle engine, and compared to a commercial oil-lubricated TC supported on FRBs. The test results showed that the GFBs increased the rotor speed by ~ 20% at engine speeds of 1,500 rpm and 1,750 rpm, yielding the reduction of turbine input energy by more than 400 W. Incidentally, an external shock test on the oil-free TC casing was conducted at the rotor speed of 60 krpm, and showed a good capability of vibration damping due to the well-known dry friction mechanism of the GFBs.

• Journal of Korea Foundry Society
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• v.42 no.6
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• pp.392-397
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• 2022

In order to compliant the stringent exhaust emission regulations, higher fuel efficiency and cleaner exhaust gas in combustion engines have been required. To improve combustion efficiency, an exhaust gas temperature is increasing, therefore higher temperature resistance is required for components in exhaust system, especially turbine wheel in turbocharger. IN100 looks quite attractive candidate as it has high temperature properties with low density, however it has low castability due to poor ductility at high temperature. In this study, the balance of Al and Ti composition was optimized from the base alloy IN100 to improve the high temperature ductility by expanding the γ single phase region below the solidification temperature, while obtaining the high temperature strength by maintaining the volume fraction of γ' phase equivalent to IN100 around 1000℃. Furthermore, the high temperature creep rupture life increased by adding a small amount of Ta. The alloy developed in this study has high castability, low density and high specific strength at high temperature.