• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1349-1358
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• 2018

In addition to responding to the environmental pollution caused by fossil fuels, the enforcement of Renewable Fuel Standard(RFS) system has increased the utilization of renewable energy such as refined fuels oil. The by-product fuel oil(No. 2) and the refined fuel oil(reduced-pressure) are strictly regulated by the domestic legislation and the chemical property changes of the refined fuel oil(reduced-pressure) mixed with the by-product fuel oil(No. 2) were analyzed. As a result of analyzing the physical properties of refined fuel oil(reduced pressure) obtained by mixing 1 : 1 of by-product fuel oil(No. 2), it satisfied the quality standards stipulated by the domestic Enforcement Decree of the Wastes Control Act. However, the results of the additional tests related to the fuel showed a high aromatic content. The high content of aromatic in a fuel is likely to cause the soot and ehaust emission gas during the combustion of the used equipment.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.332-336
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• 2008

A pulsation damper is usually mounted on the fuel rail to diminish undesirable noise in the vehicle cabin room. However, pulsation dampers are quite expensive. Therefore, several studies have focused on reducing fuel pressure pulsations by increasing the self-damping characteristics of the fuel rail. This paper is a basic study in the development of a fuel rail that can reduce pulsations via a self-damping effect. In this study, the pressure pulsation characteristics were of investigated with respect to the aspect ratio of the cross section, wall thickness, and fuel rail material through oil hammer simulations. An oil hammer simulation was performed in advance to simulate the pressure pulsations at the resonant speed, which is a time-saving way. The pressure pulsation peak of fuel rail was observed to rise as the injection period increases. Increase of the aspect ratio and decrease of the wall thickness can reduce the pressure pulsation efficiently.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.1-4
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• 2002

This article presents the unique characteristics of cavitation, those are very high pressure and very high temperature even in a very short time. Such the high-pressure causes the destruction of material, which sometimes brings a severe problem to fluid machinery. However, if we look the cavitation from the different direction, such the high pressure can be used to various applications. The author presents two examples of the utilization of cavitation recently done at the Toyo University. Those are 'dispersion of spilled oil' and 'killing planktons'.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.304-309
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• 2001

In this paper, the hydraulic oil pressure distributions are measured in the clearance gap between a stationary piston and moving cylinder apparatus. The results showed that the hydrodynamic pressure distributions are highly affected by the speed of cylinder and further experimental and analytical studies are required to obtain more accurate results. Therefore present experimental method can be used to enhance the performance of various hydraulic components adopting the piston-cylinder mechanism.

• Transactions of Materials Processing
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• v.11 no.1
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• pp.69-74
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• 2002

In addition to lightweight and moldable characteristics, polymeric foams possess an excellent energy absorbing capability that can be utilize for a wide range of commercial applications, especially in the crashworthiness of the automobiles. The purpose of the present study is to develop experimental methodology to characterize the pressure dependent yield behavior of the energy absorbing polymeric foams. For the compression test in a triaxial stress sate, a specially designed device was placed in a hydraulic press to produce and control oil pressure. For the test material, the polyurethane foams of two different densities were used. The displacement of the specimen, the load subjected to the specimen, and oil pressure applied to the specimen were measured and controlled. Stress strain curves and yield stresses for the four different oil pressure were obtained. It was found from the present experiments that the polyurethane foams exhibited significant increases in yield stress with applied pressure or mean normal stress. Based on this observation, a yield criteria which included the effect of the stress invariant were established for the polymeric foams. The obtained experimental constants which constituted the pressure-dependent yield criterion were verified.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.29-34
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• 2009

Recently, we have a lot interest in a sudden rise of oil prices and a change weather for the earth warmming, so, development of new alternative fuels need in order to spare fossil fuel and reduce exhaust emissions for air pollution prevention. Biodiesel, which can be generated from natural renewable sources such as new or used vegetable oils or animal fats, may be used as fuel in diesel engine of compression ignition engine. In this paper, the combustion characteristics between neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were tested using four stroke, direct injection diesel engine, especially this biodiesel was produced from soybean oil at our laboratory. This analysis showed that cylinder pressures, the rate of pressure rises and the rate of heat releases were decreased as the blending ratios of biodiesel to diesel oil increased because of lower heating value of biodiesel in spite of increased oxygen content in biodiesel.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.2
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• pp.243-249
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• 2010

The improvement of fuel economy and the reduction of diesel exhaust PM(Particulate Matter) and $NO_X$ have been successfully achieved by supplying diesel engines with emulsified diesel oil. However, combustion analysis of emulsified C-heavy oil is difficult because the combustion characteristics of emulsified C-heavy oil compared to other fuels have a special form. Therefore, these experimental researches have analyzed the combustion characteristics of emulsified C-heavy oil in a chamber with high pressure and temperature. The pressure and the rate of heat releases in a combustion chamber was decreased with increasing the water content and the ignition delay time was increased with increasing the water percent.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.127-138
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• 1993

This study was investigated optimal conditions which were necessary to prepare emulsion of four component systems by the Microfluidizer. Squalane, isopropyl myristate, PPG-15 stearyl benzoate ester were used as an oil and POE(20) sorbitan monolaurate, POE(20) sorbitan monopalmitate, POE(20) sorbitan monostearate, glycerine were selected as a cosurfactant and surfactant. The emulsion was affected by the operating pressure, the recycle frequency and oil, surfactant, cosurfactant phase. The operating pressure and recycle frequency increased, the droplet diameter of emulsion decreased and was constant later. In this study, the optimal pressure and recycle frequency were 1400 bar, 4 cycles. The droplet size was the smallest when the concentration of glycerine was 30 wt.%. As the oil phase is increased, the size is increased.

• Tribology and Lubricants
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• v.6 no.1
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• pp.36-51
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• 1990

A parametric study of the thermal effects of a half-circumferential grooved journal bearings under aligned and misaligned conditions has been carried out by solving numerically the coupled Reynolds and energy equation system. Five different sets of boundary conditions for the energy equation have been used which include mixing between recirculating oil and inlet oil and a contraction ratio for the cavitation region. The effects of changes of the inlet oil temperature and pressure, the wall temperature and the L/D ratio have also been examined. For the range of parameters found in internal combustion engines, the mixing effectiveness at the groove and the resulting final mixture temperature have been found to be as important as the wall temperature and the heat transfer rate. The variability of the temperature, though, has been shown to smooth out the peaks of both pressure and friction during misaligned condition Distributions of friction and pressure in the oil are also examined which may be useful in attempts to reduce friction without reducing load. Results for an axial grooved bearing are also presentsed for comparision purpose.

• Tribology and Lubricants
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• v.22 no.1
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• pp.14-19
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• 2006

VCT(Variable Cam Timing) system is one of very useful engine components to improve fuel economy and overcome emission regulation etc. In order to adapt the VCT to a base engine, many design mod ifications in the mechanical and lubrication fields are required. Especially, because the VCT performance itself depends on supplied oil flow rate and pressure, it is very important to evaluate the engine lubrication system in a viewpoint of supplied oil flow rate and pressure. In this paper, unsteady transient flow network analysis on the engine oil circuit system was carried out to do this.