• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.7
• /
• pp.722-728
• /
• 2015

The demand for shipboard energy management is expected to gradually increase based on ship energy efficiency management plans (SEEMPs), which have been in use since January 1, 2013. Therefore, the fuel consumption of the main engine, which occupies the greatest portion of the energy used, along with elements related to the engine power, should be strictly monitored. There are many different methods for indicating the engine power. However, this study performed an experiment to monitor the status of a ship's engine power in real time using an encoder and a proximate switch, which are economical to purchase and easy to install. In the experiment, the angular velocity during one cycle of a two-stroke low-speed engine was measured, and the measured data were converted to the torque fluctuation. The angular velocity during an abnormal firing condition in the cylinder was also measured, and the torque fluctuation as a result of a misfire was considered. The results were compared with sea trial data to determine the reliability. In this study, the status of the engine power was determined using the torque fluctuation of the main engine in an operating ship.

• Journal of Biosystems Engineering
• /
• v.28 no.2
• /
• pp.89-96
• /
• 2003

This study was aimed to identify how the main body vibration of power tiller will be transmitted to the trailer, and to find out the basic information for demage reducing method of agricultural products during transportation. The vertical vibration acceleration level was measured at 6 positions, i.e. engine, hitch, seal and three parts of trailer (front middle, and rear) for the not driving but at the engine speeds of 1,000rpm and driving at 0.35m/s. The results of this research could be summarized as follows; 1. For not driving, the accumulated acceleration level up to 120Hz was 50% of total accelerations at engine part and those were 28~41% at other parts. Those up to 40Hz were 20~30% at engine and hitch part and 2~8% at trailer part. And those up to 20Hz were 13~20% at engine and hitch part and 1~4% at trailer part 2. For the driving with 0.35m/s at paved road, the average vertical accelerations were in the range of 0.005~0.058m/s$^2$. The lowest value of 0.005m/s$^2$ was showed at engine part and the value of 0.031-0.058m/s$^2$ was showed at trailer part. 3. For the driving with 0.35m/s, the accumulated value of average vertical accelerations showed the lowest value at engine parts md showed 5 times value of engine part at trailer part especially highest value at middle part of trailer. 4. For the driving with 0.35m/s, the accumulated acceleration level up to 120Hz was 75% of total accelerations at engine part and those were 20~42% at other parts. Ant those up to 20Hz and 40Hz were 24~26% at engine part and 0.1~0.6% at trailer part.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.2
• /
• pp.22-27
• /
• 2007

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions of diesel engines are recognized as main causes of the air pollution. CRDI(common rail direct injection) diesel engine is widely used for the sake of minimization on exhaust emission. Because biodiesel fuel is a renewable and alternative fuel for diesel engine, its usability is expanded. In this study, a common rail diesel engine was run with 5% of biodiesel fuel(BDF 5%) more than 150 hours. Engine dynamometer testing was completed at regularly scheduled intervals to investigate the engine performance and exhaust emissions. The data of engine performance and exhaust emissions was sampled at 1 hour intervals for analysis. When a common rail diesel engine runs on BDF 5% for long time, power and energy consumption of the engine are similar to the case using diesel fuel. The smoke emission of BDF 5% was reduced in comparison with diesel fuel, that is, it was reduced approximately 15% at 4000rpm, and load of 90%. And, CO and $CO_2$ were reduced, too. On the other hand, NOx emission of biodiesel fuel was slightly increased about 2%, but it was almost same as a commercial diesel fuel.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.506-511
• /
• 2010

This paper presents development activities of the T700/701K turbo-shaft engine for Korean Utility Helicopter(KUH). The T700/701K is the first rear-drive variant of the GE's T700 engine which is proven for military applications in the world. The main workscope of the development includes a modification from a front-drive engine to a rear-drive one, an performance enhancement of the power turbine and an incorporation of two channel FADEC(Full Authority Digital Engine Control) system for more reliable operation. The first engine run for development and qualification test was successfully completed in 2008. Since the PFRT(Preliminary Flight Rating Test) has been completed, the first flight of the engine installed in the first prototype of KUH has been successfully demonstrated in March, 2010 and the engine installation compatibility tests are being carried out during KUH flight test. The test and evaluation for qualification of the engine has been done except for the LCF test up to date.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.79-87
• /
• 2017

Korea Aerospace Research Institute has being developed a staged combustion cycle rocket (SCCR) engine with high specific impulse to send a 3-ton class satellite into geostationary orbit while conducted Korean Space Launch Vehicle (KSLV) II project. The SCCR engine is different from the KSLV-II engine, which is open cycle engine using a gas-generator. The SCCR engine with closed cycle is composed of a pre-burner, a turbo pump, and a main combustor. The technology demonstration model (TDM0) was assembled and tested in the 7ton-class engine combustion test facility of Naro Space Center, and the combustion test was successfully conducted. Afterward engine-shaped SCCR engine model (TDM1) is being designed and developed for the next combustion test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.369-375
• /
• 2004

Gas turbine engine simulation in terms of transient, steady state performance and operational characteristics is complex work at the various engineering functions of aero engine manufacturers. Especially, efficiency of control system design and development in terms of cost, development period and technical relevance implies controlling diverse simulation and identification activities. The previous engine simulation has been accomplished within a limited analysis area such as fan, compressor, combustor, turbine, controller, etc. and this has resulted in improper engine performance and control characteristics because of limited interaction between analysis areas. In this paper, we propose a new simulation methodology for gas turbine engine performance analysis as well as its digital controller to solve difficulties as mentioned above. The novel method has particularities of (ⅰ) resulting in the integrated control simulation using almost every component/module analysis, (ⅱ) providing automated math model generation process of engine itself, various engine subsystems and control compensators/regulators, (ⅲ) presenting total sophisticated output results and easy understandable graphic display for a final user. We call this simulation system GT3GS (Gas Turbine 3D Graphic Simulator). GT3GS was built on both software and hardware technology for total simulation capable of high calculation flexibility as well as interface with real engine controller. All components in the simulator were implemented using COTS (Commercial Off the Shelf) modules. In addition, described here includes GT3GS main features and future works for better gas turbine engine simulation.

• Journal of Navigation and Port Research
• /
• v.42 no.6
• /
• pp.415-420
• /
• 2018

The Energy Efficiency Design Index (EEDI) introduced by the Marine Environment P rotection Committee(MEPC) in International Maritime Organization(IMO) has significantly assisted in regulating CO2 emissions. However, in adverse weather conditions, it can lead to accidents due to slow steaming of vessels and low engine propulsion power. In response to this issue, the MEPC presented guidelines for the minimum propulsion power of the main engine for maintaining the course of vessels in adverse weather conditions. However, the guidelines are only applicable for vessels with a deadweight of 20,000 tons, leaving out small and medium ships. This study evaluated vessels subject to the guidelines of minimum propulsion power and proposed revised guidelines. In addition, relevant cases of marine accidents were investigated with the aim of investigating the minimum propulsion power of main engine for medium and small ships not covered by the guidelines. In order to achieve this, engine propulsion power was analyzed according to the size of the affected vessels. The results obtained from this study could be used as a minimum power criterion that can be considered for ship building to reduce marine accidents in adverse weather for small and medium ships.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.22 no.3
• /
• pp.109-118
• /
• 2018

Korea Aerospace Research Institute has developed a staged combustion cycle rocket (SCCR) engine with high specific impulse to send a 3-ton class satellite into geostationary orbit while conducting a Korean Space Launch Vehicle (KSLV) II project. The SCCR engine is different from the KSLV-II engine, which is an open cycle engine using a gas-generator. The SCCR engine with a closed cycle engine is composed of a pre-burner, a turbo pump, and a main combustor. The technology demonstration model (TDM0) was assembled and tested in the 7ton-class engine combustion test facility of Naro Space Center, and the combustion test was successfully conducted.

• International Journal of Automotive Technology
• /
• v.7 no.4
• /
• pp.407-413
• /
• 2006

The liquefied petroleum gas(LPG), mixture of propane and butane, has the potential to reduce toxic hydrocarbon emissions and inhibit ozone formation due to its chemical composition. Conventional mixer systems, however, have problems in meeting the future lower emission standards because of the difficulty in controlling air-fuel ratio precisely according to mileage tar accumulation. Liquid Phase LPG injection(LPLi) system has several advantages in more precise fuel metering and higher engine performance than those of the conventional mixer type. On the other hands, leakage problem of LPLi system at the injector tip is a main obstacle for meeting more stringent future emission regulations because these phenomena might cause excessive amount of THC emission during cold and hot restart phase. The main focus of this paper is the development of a leaked fuel recirculation system, which can eliminate the leaked fuel at the intake system with the activated carbon canister. Leaked fuel level was evaluated by using a fast response THC analyzer and gas chromatography. The result shows that THC concentration during cold and hot restart stage decreases by over 60%, and recirculation system is an effective method to meet the SULEV standard of the LPLi engine.

• 한국연소학회:학술대회논문집
• /
• 2003.05a
• /
• pp.27-32
• /
• 2003

Diesel-Fueled HCCI(Homogeneous Charge Compression Ignition) Engine is an advanced combustion process explained as a premixed charge of diesel fuel and air is admitted into the cylinder and compression ignited. It has possibility to reduce NOx by spontaneous auto-ignition at multiple points that allows very lean combustion resulting in low combustion temperatures. Also PM could be reduced by the premixed combustion and no fuel-rich zones. But HCCI couldn't be realized because of the difficulties in vaporizing the diesel, control of combustion phase directly. To solve these problems, new fuel injection strategy, explained as the pilot fuel injection to promote ignition near TDC following the main fuel injection at the extremely advanced timing, is applied during the compression ratio is varied from 18.9:1 to 27.7:1 This is not a pilot fuel to promote the ignition but also the direct control method of the combustion phase. Experimental result shows the pilot fuel injection promote the ignition and the compression ignition of the HCCI engine is achieved as compression ratio becomes higher. Also there is an optimal pilot fuel injection timing for the HCCI combustion. NOx is reduced more than 90% compared to DI-Diesel case but PM and THC emission needs more investigation.