• Tribology and Lubricants
• /
• 제22권4호
• /
• pp.203-210
• /
• 2006

Two kinds of crankshaft oil supply system which were called continuous and discontinuous oil sup-ply system have recently been adopted in engine developing process. In order to clarify the lubrication characteristics for theses systems, in this paper, the comparison studies on supplied oil temperature, pressure, aspect ratio of bearings, and radial clearance were carried out for the main and the connecting rod bearing using computational fluid dynamic analysis.

• Tribology and Lubricants
• /
• 제24권4호
• /
• pp.170-178
• /
• 2008

In this paper, it is described how the problems appeared at the previous proto type sensor are improved. As changing the pressure and temperature of engine oil in a test rig, the modified sensor is tested. Then, the measured results of capacitance and the corresponding dielectric constants under various temperatures and pressures are shown. It turns out that the electrical signal gotten from the electrodes of newly developed sensor can be more stable under the various operating conditions.

• 한국안전학회지
• /
• 제12권2호
• /
• pp.22-26
• /
• 1997

A small scale centrifugal oil separator consisted of two concentric tubes was fabricated for spilt oil recovery. With speed control of the inner tube, its performance of oil separation was investigated. Oil-water mixture is separated by forced vortex motion with the rotating inner tube. Velocity and pressure distributions in the tubes were calculated. Control of rotating speed, which is the most influencing parameter, showed an optimum value 946rpm corresponding to the acceleration of 20g at the inner tube surface. Separation performance was suddenly deteriorated at rotating speed higher than 1200rpm.

• Tribology and Lubricants
• /
• 제13권2호
• /
• pp.46-51
• /
• 1997

Crosshead bearings in two-stroke marine diesel engines are operated under severe conditions of lubrication because the load on the bearing is unidirectional and the sliding speed is very low and oscillatory. In this paper, the motion of journal in a bearing is investigated using the lubrication theory. Several locus paths are presented to show the effects of oil groove size, bearing clearance and oil inlet pressure. It is found that the minimum film thickness is affected by the oil groove and bearing clearance, and the oil groove is an important design factor.

• 한국자동차공학회논문집
• /
• 제2권3호
• /
• pp.85-93
• /
• 1994

The engine performance and combustion characteristics of diesel oil and fish oil blended with diesel oils were investigated at various blending rate of fish oil in a diesel engine. The maximum pressure showed no significant difference among test fuels at low load, but it was higher as the blending rate of fish oil increases at high load. Increasing the blending rate of fish oil, the rate of heat release and burned fraction were higher than those of diesel oil. The ignition delay became longer than that of diesel oil as the blending rate of fish oil increases, and its differences were larger at different loads. The combustion duration and density of smoke were shorter and lower as the blending rate of fish oil increases. The rate of fuel consumption showed no significant difference between diesel oil and fish blended with diesel oils.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
• /
• pp.33-34
• /
• 2005

The internal state of an automotive engine is very severe. A piston exposes burnt gas of over $2000^{\circ}$ nd is shocked by high pressure at the time of explosion. Furthermore strong friction is caused by high speed motion. A study on the cooling of the piston requires because the cooling and lubrication of the piston has an effect on the life and efficiency of engine directly. The previous system of oil jet cooled only the bottom of the piston. In order to improve the cooling efficiency, the oil gallery is made inside the piston, and oil flows into the oil gallery. The flow rate of oil at the entrance of oil gallery is important because of the cooling efficiency. The purpose of this study is the investigation of fluid flow characteristics of oil jet and flow rate into the oil gallery.

• 한국전산유체공학회지
• /
• 제19권4호
• /
• pp.8-13
• /
• 2014

A series of numerical simulation has been carried out to study performance of a cyclone type oil separator, which is designed for the compressor of a refrigeration system. Working fluid is R22, which is a typical refrigerant, and mineral oil droplet is supplied. Pitch of the helix is considered as design parameters to make a compact separator. Depending on the helix pitch, separation efficiency varies from 97.5 to 99%, while predicted pressure drop ranges from 5 to 6.5 kPa. Considering both of the pressure drop and separation efficiency, helix pitch of the separator has been designed as 50 mm.

• 에너지공학
• /
• 제12권3호
• /
• pp.216-222
• /
• 2003

실험실 규모의 진공 증발 수분 제거 시스템을 이용하여, 압력, 윤활유의 온도, 초기 수분농도 및 윤활유 분사 노즐의 형태 등 폐윤활유 속에 포함된 수분 제거 성능에 영향을 미치는 각각의 운전 변수들에 대한 실험적인 연구를 수행하였다. 연구의 결과 압력 및 폐윤활유 온도의 증가는 수분 제거 성능에 매우 중요한 변수임을 확인하였으며, 또한 진공 증발실로 폐윤활유를 분사하기 위한 노즐의 형태는 다공성 매질의 노즐 형상인 경우가 가장 우수한 수분 증발 성능을 나타내었다.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
• /
• pp.105-110
• /
• 1999

The elementary experiment was performed to develop the emulsified fuel production system using pressure injection nozzle in this study. The stabilities and characteristics of emulsified fuel which is produced through direct spray of water via pressure injection nozzle into oil are examined. To understand performance of emulsion production, stabilities of emulsified fuel which is made by adding water to the mixed fuel of Bunker-C and 10 $^{\sim}$ 50 vol% of heating oil were investigated. According to volume ratios of surfactant in heating oil the stability and SMDs were measured

• Food Science and Biotechnology
• /
• 제16권6호
• /
• pp.999-1005
• /
• 2007

An oil-in-water (O/W) emulsion [20 wt% com oil, 0.5-6.0 wt% fish gelatin (FG), pH 3.0] was produced by high pressure homogenization, and the influence of pH, protein concentration, and homogenization condition on the formation of FG-stabilized emulsions was assessed by measuring particle size distribution, electrical charge, creaming stability, microstructure, and free FG concentration in the emulsions. Optical microscopy indicated that there were some large droplets ($d>10\;{\mu}m$) in all FG-emulsions, nevertheless, the amount of large droplets tended to decrease with increasing FG concentration. More than 90% of FG was present free in the continuous phase of the emulsions. To facilitate droplet disruption and prevent droplet coalescence within the homogenizer, homogenization time was adjusted in O/W emulsions stabilized by 2.0 or 4.0 wt% FG. However, the increase in the number of pass rather promoted droplet coalescence. This study has shown that the FG may have some limited use as a protein emulsifier in O/W emulsions.