• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1547-1551
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• 2011

The EFI small engine has been redesigned and manufactured based on a commercial small engine with a carburettor. Performance development of the EFI small engine has been conducted to optimize the operating conditions. Maximum torque and power were 12.56Ps and 25.4Nm, respectively, that were equivalent with carburettor type engine. Brake specific fuel consumption of the EFI small engine has been improved 17% on average compared with that of base small engine with a carburettor. By conducting KG2-6 mode test,HC+NOx was 7.46g/kWh that satisfied EPA Phase 3 regulation. THC has been reduced 41% on average, but NOx has been increased 3.5 times on average due to the improved thermal efficiency.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.201-207
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• 2012

This study was carried out to improve the design of heat exchanger for small marine diesel engine. As air pollutants emitted from small marine diesel engine become international problem, IMO(International Marine Organization) tried to establish severe regulations for NOx reduction. The formation of NOx is affected by cooling system, for instance, such as intercooler, heat exchanger, exhaust manifold, and therefore cooling systems are one of essential parts for design of small marine diesel engine. In this study, heat exchanger for small marine diesel engine was modeled and simulated using CATIA V5R19 and ANSYS FLUENT V.13. Thermal flow simulation for heat exchanger was performed to find the optimal design. As the results, maximum velocity of engine coolant in shell inside was 9.1m/s and it was confirmed that outlet temperature and temperature drop for engine coolant could be calculated by simulating proportional relations of temperature between engine coolant and sea water.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.5
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• pp.79-84
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• 2011

Air pollutants from a small marine diesel engine are increasing and the IMO(International Marine Organization) regulation asked for its reduction. In this study, NOx reduction technologies such as improvement of various cooling systems are applied to the small marine diesel engine. The various cooling systems are a intercooler, a heat exchanger for engine coolant, and an exhaust manifold by water cooling. These systems are tested on an engine dynamometer and a exhaust gas analyzer by a marine diesel engine test regulation. Test results are shows that the small marine engine are satisfied the IMO NOx regulations; Tire II.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.69-76
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• 2001

VCO nozzle is devised to minimize the HC emission and has been applied on some HSDI diesel engines. But it is not well reported whether VCO nozzle would be advantageous over SAC nozzle in a small HSDI diesel engine. In this paper it is presented that characteristics of VCO and SAC nozzle under common rail fuel injection system and their effects on the performance in a small HSDI diesel engine.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.4
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• pp.36-42
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• 1996

Analysis of heat transfer on small-size Diesel engine is required for the development of high performance and efficiency engine. This basic study aims to establish heat transfer technique for marine Diesel engine. The main results from this study are as follows : 1) Overall engine heat transfer correlation of Re-Nu. 2) Radiant heat flux as fraction of total heat flux over the load range of several different Diesel engine. 3) Characteristics of heating curves on piston, cylinder liner and head. 4) Surface heat flux versus injection timing.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2916-2921
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• 2008

This paper presents the performance and characteristics of small spark-ignited small 2-stroke engine. A single cylinder, two-stroke, air cooled 23cc SI engine for brush-cutter was used in this study. For the performance of the engine, rpm, torque, fuel consumption and lubricate oil consumption were measured, and also HC, CO, NOx emissions and excess air ratio according to throat open ratio under two lubrication method were measured and analyzed. The results showed that maximum of engine rpm is nearly same in both methods and also, torque, power is similar. exhaust emissions tend to decrease with throat open ratio.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.127-132
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• 1984

Performance tests of small diesel engine were carried out, using the blend fuel oil as the substitute fuel oil and the following results were obtained. (1) The character at the blend oil as substitute fuel for small diesel engine was examined. (2) In the case of operating small diesel engine with blend oil, the exhaust gas volume increases at 8% in comparison with diesel oil. (3) In the case of operating small diesel engine with blend oil, the fuel consumption Increases at 3% in comparison with diesel oil. (4) In the brake thermal efficiency, blend oil is similar to diesel oil.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.1 s.20
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• pp.49-55
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• 2005

Due to small and light mission payloads, subsystems and propulsion system, small sized UAVs come to be available for reconnaissance that have been performed by aircraft and huge UAVs. The objective of this study is to develop an efficient propulsion system for small reconnaissance UAVs. A glow engine was modified for an efficient and robust 4-stroke gasoline engine with carburetor, new electronic control unit and lubrication system. Engine modification technique and small engine performance test stand are capable of economical method for military UAVs.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.6
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• pp.42-49
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• 2014

Test device using virtual engine simulator can help reduce the number of engine tests through tests similar to the actual engine tests and repeat the test under the same condition, and thus reduce the engine maintenance and operating costs. Also, as it is possible to easily implement extreme conditions in which it is hard to conduct actual tests, it can prevent engine damages that may happen during the actual engine test under such conditions. In this study, an upgraded small jet engine performance test device was developed that can conduct both real and virtual engine test by applying real-time engine model to the existing micro jet engine performance test device that was previously developed by authors. This newly developed multi-purpose small jet engine performance test device is expected to be used for various educational and research purposes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2005-2010
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• 2011

Since recently exhaust gas regulation for a non-road small engine as well as commercial vehicle engine has been enforced, a carburettor of a small engine should be replaced by an electronic fuel injection system. In this study, the spray characteristics of the 400cc gasoline small engine injector has been experimentally analyzed. Based on the experimental results, suitable injector for the small engine has been selected. Through the test rig measuring spray mass distribution, fuel distribution characteristics of 3 hole- and 6 hole-injector has been analyzed. Through the visualization equipment, injector spray angle, penetration length and spray width have been measured and analyzed. Considering spray characteristics and stability, 6 hole-injector is selected for the 400cc gasoline small engine.