The purpose of this study was compared the spray, combustion and emissions (NOx, CO, HC, smoke) characteristics of a typical fuel (100% Diesel, DME) and Diesel-DME blended fuel in a Constant Volume Chamber (CVC) and a single-cylinder DI diesel engine. Spray characteristics were investigated under various ambient and fuel injection pressures when the Diesel-DME blended ratio is varied. The parameters of spray sturdy were spray shape, penetration length, and spray angle. Common types of injectors having seven holes and made by Bosch were used. As of use, the typical fuel (100% Diesel, DME) and the blended fuel by mixture ratio 95:5, 90:10 (Diesel:DME) were used. The Injection pressure was fixed by 70.1MPa, when the ambient Pressure was varied 0.1, 2.6 and 5.1 MPa. The combustion experiments was conducted with single cylinder engine equipped with common rail injection system. injection pressure is 70 MPa. The amount of injected fuels is adjusted to obtain the fixed input calorie value as 972.2 J/cycle in order to compare with the fuel conditions.

To comply with the regulation of the reinforcing Clean Air Conservation Act, it is necessary for the semiconductor manufacturers to develop effective low-concentration acid gas abatement system to treat the flue gas. The low-concentration acid gas was found to be harder to deal with than the high-concentration one. In this study, the effect of various potential treatments such as air-assist nozzle spraying, magnetizing the scrubbing water, and adding surfactants to spraying and scrubbing water were investigate through the application of the statistical ANCOVA method, which was proved to be very useful tool when the inlet concentration of acid gas could not be controlled precisely and it affected the removal efficiency of the abatement system.

In this paper, high-pressure injection characteristic of servo hydraulic injector as the key component of diesel CRDi system, which is driven by solenoid and piezo-actuator were examined by experimental analysis. High-pressure injection characteristic of standard diesel fuel injected at high pressure up to 160 MPa was investigated at high-pressure chamber by using a high-speed camera for spray visualization and quantitative analysis. By this study, we found that the piezo-driven injector has better performances in controlling the fuel injection with the high pressure, including fuel quantity, spray penetration length and spray velocity, than that of a solenoid-driven injector. In particular, the needle response time for start of injection in piezo-driven injector was faster of about $125{\mu}s$ than that of solenoid-driven injector. Consequently, it is known that the piezo-driven injector has more degrees of freedom in controlling the fuel injection with the high pressure than solenoid-driven injector.

The spherically-symmetric burning of an isolated droplet is a dynamic problem that involves the coupling of chemical reactions and multi-phase flow with phase change. For the improved understanding of these phenomena, this paper presents the numerical results on the n-heptane droplet combustion conducted at a 1 atm ambient pressure in three different initial droplet diameter ($d_0$). The main purpose of this study is to provide basic information of droplet burning, extinction and flame behavior of n-heptane and improve the ability of theoretical prediction of these phenomena. To achieve these, the numerical analysis was conducted in terms of normalized droplet diameter ($d/d_0$), flame diameter ($d_f$) and flame standoff ratio (FSR) under the assumptions that the droplet combustion can be described by both the quasi-steady behavior for the region between the droplet surface and the flame interface and the transient behavior for the region between the flame interface and ambient surrounding.

While variable valve actuation or variable valve lift (VVL) is used increasingly in spark ignition (SI) engines to improve the volumetric efficiency or to reduce the pumping losses, it is necessary to understand the impact of variable valve lift and timing on the in-cylinder gas motions and mixing processes. In this paper, characteristics of the in-cylinder flow and fuel distribution for various valve lifts (4, 6, 8, 10 mm) were simulated in a GDI engine. It is expected that the investigation will be helpful in understanding and improving GDI combustion when a VVL system is used. The CFD results showed that a increased valve lift could significantly enhance the mixture and in-cylinder tumble motion because of the accelerated air flow. Also, it can be found that the fuel distribution is more affected by earlier injection (during intake process) than that of later injection (end of compression). These may contribute to an improvement in the air-fuel mixing but also to an optimization of intake and exhaust system.

Adulterations fuel have been using in the vehicle in these days. Because gasoline, diesel prices are rising every day. so people find more cheap price fuel. Adulterations fuel caused a serious air pollution problems. Adulteration fuel were made from waste engine oil, waste paint. According to Government regulations permit to be used recycle fuel(adulteration fuel) only in industrial boiler. Unburned fuel pollutants are effected to human health. In this paper, the hazardous air pollutants characteristics in the diesel vehicles according to adulterations of vehicle fuels were carried out in the NEDC test mode in chassis dynamometer. It is revealed that the all of the regulation pollutants (THC, NOx, CO and PM) emission in the adulterations of vehicle fuels was increased also the green house gas, $CO_2$ was increased. In the hazardous air pollutants characteristics, the VOCs(Volitile Organic Compounds) BTEX(Benzene, Toluene, Ethylbenzene, Xylene) emissions in the adulterations of vehicle fuels showed higher level than these in the diesel fuels.