• 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.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.8
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• pp.824-833
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• 2012

The shrinkage and the warpage of the moulded part are influenced by the design of the product and injection mould. In a flat part with a partly thick volume, the warpage of the flat part is created from the difference of the shrinkage between thin and thick regions. The warpage of the flat part with a partly thick volume can be reduced by a proper design of the cooling system in the injection mould. The goal of this paper is to design properly cooling channels of injection mould to manufacture a flat part with a partly thick volume. The conformal cooling channel is adopted to improve cooling characteristics of a region with the thick volume. The linear cooling channels are assigned to the other region. The proper design of the conformal cooling channels is obtained from three-dimensional injection molding analysis for various design alternatives. The moulding characteristics of the designed mould with both conformal and linear cooling channels are compared to those of the mould with linear cooling channels from viewpoints of temperature, shrinkage and warpage of the moulded part using numerical analysis. Injection mould with both conformal and linear cooling channels for the flat part with a partially thick volume is fabricated. In addition, injection moulding experiments are performed using the fabricated mould. From the results of the injection moulding experiments, it has been shown that the designed mould can successfully fabricate the flat part with a partially thick volume.

• Journal of Pharmaceutical Investigation
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• v.30 no.3
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• pp.223-228
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• 2000

Testing the volume of injection in container is to ensure that the nominal content of a container can be administered to the patient. The method to test the volume of injection in container is described in European Pharmacopeia (EP) and United States Pharmacopeia (USP). However there is no method to test the volume of injection in Korean Pharmacopeia (KP). So we surveyed the method practiced by 53 pharmaceutical companies in Korea by a questionnaire and tested commercially available injections by discharged volume. As the result, we agreed with the International Conference on Harmonization (ICH) test method for discharged volume. It was suggested that the ICH test method for discharged volume of injection in container would be adopted.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.6
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• pp.191-197
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• 2006

This study is to establish a standardization of injection system by inorganic material for crack repair of tunnel concrete structures. For this various surveys and experiments were carried out as followed. The first we surveyed capability of injection and crack pattern of concrete structures in site. and second we analyzed the relationship between crack width and volume of injection, and decided pressure and volume of injection. Finally we evaluated the relationship between crack width and volume of injection with kind of concrete structures, and between required time for injection and crack width with thickness of structure. From these surveys and experiments, we cleared the relationship between crack patterns and injection technologies such as volume, pressure of injection and required time for injection with kind of structure.

• Journal of Industrial Technology
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• v.32 no.A
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• pp.65-70
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• 2012

Carboxy-guns are used for rapid and precise injection of $CO_2$ gas to the target skin area using external power source. In the design of carboxy-gun, the most important thing is how to precisely control injection volume of $CO_2$ gas. This paper deals with the control scheme of injection volume of carboxy-gun using solenoid valve. First the amount of volume that passes through the solenoid valve under on-off time ratio control is estimated based on the assumption of compressible gas flow. The flow rate of gas is experimentally measured under the varying pressure of the gas reservoir. Two results showed good correlation to each other, thus demonstrating the validity of the volume control strategy.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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• pp.102-109
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• 1994

As a fundamental study to apply high pressure injection system to direct injection diesel engine, fuel injection system and constant volume combustion chamber were made and the behaviors of evaporating spray with the variation of injection pressure and the ambient gas temperature were observed by using high speed camera, and the combusion characteristics with the variation of injection pressure and A/F ratio were analyzed. As injection pressure increases, spray tip penetration and spray angle increase and, as a results spray volume increases. This helps an uniform mixing of fuel and air. Spray liquid core length decreases as ambient gas temperature increases, while it decreases as injection pressure increases but the effect of ambient gas temperature is dorminant. As injection pressure increases, ignition delay is shortened and combustion rate being raised, maximum heat release rate increases. It become clear that High injection pressure has high level of potential to improve the performance of DI-diesel engine.

• Journal of ILASS-Korea
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• v.22 no.3
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• pp.109-115
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• 2017

The aim of this study is to investigate the effect of physical properties of fuels on spray characteristics in the gasoline direct injection system. Injection rate, spray visualization, and spray pattern experiments were performed to analyze the spray characteristics of ethanol, gasoline, and ethanol/gasoline blends. We measured injection rate of each fuel via the Bosch method. The spray visualization experiment was also carried out at atmospheric pressure using a high-speed camera. Finally, the average of drop surface area per unit volume was measured using the optical patternator. The experimental results from Bosch method showed that peak injection rate increased when the volume fraction of ethanol increased. In addition, higher viscosity of ethanol than that of gasoline leads to longer injection delay. At the initial injection region before reaching 0.8 ms, the spray tip penetration becomes longer as increasing the volume fraction of ethanol, but reversely shorter after 0.8 ms. It was found that ethanol makes spray angle become larger. The surface area per unit volume of the drop was decreased as the distance from the injection tip or the concentration of the gasoline increased.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.4
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• pp.444-453
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• 2015

In the previous study, several problems were observed in a NG conversion vehicle, which were fail of air-fuel ratio closed loop control, aggravated fuel economy, increased harmful emission and declined roadability. It was provisionally supposed that the mismatch of injection system with the engine caused these performance deterioration. In this context, the characteristics of fuel injection system of commercial conversion kit for NG were investigated experimentally varying the engine speed, fuel rail pressure and volume. The results are as follows; The injection quantity decreases as the engine speed increases due to the extremely small rail volume of the presenting system and flow rate of No. 2 injector are always lower than that of the other ones regardless of the speed under the dynamic operation condition. Furthermore the existing system does not meet the required fuel quantity for the normal engine operation over 3000 RPM. On the other hands, the large rail volume systems ease and/or eliminate the difference of injection quantity between the injectors according to the speed variation, however, these systems decrease injection flow rate and still cannot supply sufficient fuel. Finally, suitable combination of the higher rail pressure and the larger rail volume might be a solution about these problems.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.466-475
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• 2009

A numerical analysis of reactive flow in a liftoff flame is accomplished to elucidate the characteristics of flame propagation velocity and volume integral of reaction rate with the variation of fuel injection velocity at the fuel rich region, fuel lean region and diffusion flame region. The increase of fuel injection velocity enhances flame propagation velocity, but its effect on the flame propagation velocity is not much greater under 4%. The increase of fuel injection velocity affects directly and linearly on the flame surface area in the fuel rich region and so enhances volume integral of reaction rate to accommodate the increment of fuel.

• Journal of the Korean GEO-environmental Society
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• v.18 no.6
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• pp.5-19
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• 2017

In this study, the effect of rock mass curtain grouting was investigated by analyzing the correlation between the parameters of the RMR & grout injection volume, Lugeon value & RQD, Lugeon value & cement injection volume. In order to investigate the effect of rock mass curtain grouting, we analyzed the grout injection volume of 315 curtain grouting holes at 9 tunnel face of NATM Subsea tunnels in gneiss area. The total grout injection volume in the Subsea tunnels study was slightly changed in some tunnels face but decreased with increasing the rating of parameters in spacing of discontinuity (R3, Js) and groundwater condition (R5). The geological anomalies of seismic survey (3D, TSP) and the inflow of probe hole were found to be more correlated of relative than the parameters of RMR. The unit injection volume was found to decrease with higher ratings in the parameters of the RMR except the weathering degree of the discontinuity (Jc, R4). The correlation between RQD and Lugeon values is not significant, but it can be confirmed that the Lugeon value tends to decrease as the RQD value increases.