• Journal of ILASS-Korea
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• v.15 no.1
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• pp.8-16
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• 2010

This paper present the diesel spray characteristics at different injection system parameters in a HSDI diesel engine. The spray characteristics was calculated by the coupled simulation of fuel injection system model and three-dimensional KIVA-3V code with TAB spray model. The relevant injection parameters are accumulator volume, control chamber initial volume, control orifice diameter, needle valve diameter and nozzle chamber initial volume, etc. Parametric investigation with respect to twelve relevant injection parameters showed that there was a significant advantage in varying control chamber initial volume, control chamber orifice diameter, and nozzle chamber orifice diameter with respect to effect the SMD and fuel injection speed. Consequently, in order to design the fuel injection system for spray characteristics, it seems reasonable to suppose to be optimized the fuel injection system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.2
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• pp.308-318
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• 1988

The liquid disintegration and characteristics of atomization through the swirl nozzle is affected by injection pressure and injection time when the liquid is injected intermittently. These transient phenomena are investigated by electronic controlled-fuel injection nozzle. The effect of injection conditions on disintegration of liquid injected through nozzle is observed photographically by using delay circuit. Droplet size of the element of the sample is measured by the liquid immersion sampling technique. SMD of droplets is varied with time and is decreased as the injection pressure increases. As the injection pressure increases, the maximum diameter of droplet and diameter of droplet which has the maximum droplet number decrease. Spray angle is not affected on injection pressure and change of spray angle with time is associated with needle movement.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.12 no.1
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• pp.1-6
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• 1976

To investigate the relation of $NO_x$ emission and consumption rate in a direct injection diesel engine with a multihole nozzle under same fuel consumption and rpm, a naphthyl ethylenediaming method on NO, emission and Tektronix oscilloscop on the indicator diagrams have been used. Comparisons of the $NO_x$ emission and fuel consumption rate made on various conditions have led to the fllowing results. 1. The higher the injection pressure in the later injection time the lower $NO_x$ emission and the fuel consumption rate have been attained. 2. By the change of nozzle hole diameter under the same injection pressure, the $NO_x$ emission was much more lowered in the small diameter than large one, but fuel consumption rate was in inverse proption to the $NO_x$ emission. 3. The effect of injection spray angle, $\frac{1_n}{d_n}$ on $NO_x$ emission, fuel consumption rate under same injection time and injection pressure was neglectable.

• Journal of ILASS-Korea
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• v.12 no.1
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• pp.45-57
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• 2007

This paper presents both experimental and numerical studies regarding nozzles used for the SI engine application, particularly for the intake-port fuel injection type. The atomization mechanism of the multi-hole plate nozzle was investigated experimentally. It was found that the nozzle design added turbulence into the liquid-film jet and the jet disintegrated rapidly. Based on the results, various plate types for the nozzle were developed and tested; six hole nozzle for liquid jet interaction, plate-type nozzle with flat duct channel, and the simpler structured nozzle. The spray characteristics of the prototype nozzles were examined experimentally while the internal flow of the nozzle was investigated computationally. It was shown that turbulent liquid-film was injected and atomization quality was improved by controlling the internal flow condition of the plate-type nozzle.

• Journal of ILASS-Korea
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• v.7 no.1
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• pp.1-6
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• 2002

This study has focused on using fuel injections as variables for measuring performance and reducing exhaust gas in turbo-charger diesel engine. In experiments, we changed nozzle hole diameter, diameter of an injection pipe, and injection timing as variable. The results show that torque. fuel consumption and smoke are reduced as nozzle hole diameter decreases, while NOx increases. When the diameter of injector is reduced, torque, fuel consumption and smoke are deteriorated, but NOx is decreased. In addition, when the time for injection is advanced. torque, fuel consumption and smoke are improved, but the density of NOx is increased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.3
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• pp.353-358
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• 1995

The emission characteristics of a semi-Bunsen type burner for gas boilers were studied experimentally. The experimental results reveal that nitric oxide emission increases with fuel flow rate. It is linearly proportional to total fue flow rate at a small amount of fuel up to 0.4 liters per minute. It does not change significantly within the range of fuel flow rate from 0.4 to 1.2 liters per minute per nozzle and increases at large fuel flow rate. The carbon monoxide emission reveals to be dependent upon the fuel flow rate per each nozzle and the number of fuel injection nozzles. Diameter of an injection nozzle could have an effect on the emission characteristics of this type of burners. However, there is no marked change in the nitric oxide emission if the total fuel flow rate is same with different nozzle sizes.

• Journal of Power System Engineering
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• v.2 no.1
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• pp.25-30
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• 1998

In order to investigate the droplet size distribution and Sauter Mean Diameter in a ultra high pressure diesel spray, fuel was injected with ultra high pressure into the environments of high pressure and room temperature by an Electronic Hydraulic Fuel Injection System. Droplet size was measured with the immersion liquid sampling technique. The immersion liquid was used a mixture of water-methycellulose solution and ethanol. The Sauter Mean Diameter decreased with increasing injection pressure, with a decrease environmental pressure (back pressure) and nozzle diameter. Increasing the injection pressure makes the fuel density distribution of the spray more homogeneous. An empirical correlation was developed among injection pressure, air density, nozzle diameter and the Sauter Mean Diameter of spray droplets.

• Journal of ILASS-Korea
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• v.20 no.1
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• pp.43-52
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• 2015

Experimental study was conducted to investigate the effects of ultra-high injection pressure and nozzle hole diameter on diesel flow and spray characteristics. Electronically controlled ultra-high pressure fuel injection system was made to supply the fuel of ultra-high pressure consistently. Three injection pressures, 80, 160, and 250MPa were applied. Four type of injectors with identical eight nozzle holes were used. The four injectors have nozzle hole diameters of 115, 105, 95, and $85{\mu}m$ respectively. Injection quantity and rate were measured to investigate flow characteristics according to injection pressures and nozzle hole diameters. Mie-scattering and shadowgraph were performed to visualize liquid and vapor phases of diesel spray in a constant volume combustion chamber (CVCC). Ambient conditions of high pressure and high temperature in a diesel engine were simulated by using CVCC.

• Journal of ILASS-Korea
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• v.8 no.2
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• pp.1-6
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• 2003

The liquid phase LPG injection (LPLI) system (the third generation technology) has been considered as one of the next generation fuel supply systems for LPG vehicles, since it has a very strong potential to accomplish the higher power, higher efficiency, and lower emission characteristics than the mixer type(the second generation technology) fuel supply system However. when a liquid LPG fuel is injected into the inlet duct of an engine, a large quantity of heat is extracted due to evaporation of fuel. This leads to freezing of the moisture in the air around the outlet of a nozzle, which is called icing phenomenon. It may cause damage to the outlet nozzle of an injector or inlet valve seat. In this work, the experimental investigation of the icing phenomenon was carried out The results showed that the icing phenomenon and process were mainly affected by humidity of inlet air instead of air temperature in the inlet duel. Also, it was observed that the total ice formed around the nozzle weighs at about $150mg{\sim}260mg$ after injection for ten minutes. And some fuel species were found in the ice attached at the front side of a nozzle, while frozen ice attached at the back of a nozzle was mostly' consisted of moisture of inlet air. Therefore, some frozen ice deposit. detached from front nozzle of an injector, may cause a problem of unfavorable air fuel ratio control in the small LPLI engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.1-7
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• 2002

Recently, many researches for the improvement of DI diesel engines have been performed to reduce the fuel consumption and exhaust emissions. Among the various factors effect on combustion and emission in Dl diesel engines, one of the most important factors is the characteristics of the fuel spray. Accordingly, the investigation on the characteristics of spray is needed to analyze the diesel combustion exactly, In this study, the measurement technique fur injection rate using the Zeuch method was developed. In addition, the effects of nozzle hole number on the spray and flame were investigated by visualization experiment.