• Geophysics and Geophysical Exploration
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• v.19 no.1
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• pp.29-36
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• 2016

Recently, the studies about rock physics model (RPM) in shale reservoir are widely performed. In shale reservoir, the degree of the maturity can be estimated by kerogen and GOR (Gas-Oil Ratio). The researches on the rock physics model of shale reservoir with the amount of kerogen have been actively carried out but not with GOR. Thus, in this study, we analyzed the changes in seismic velocity and density, and AVO (Amplitude Variation with Offset) response depending on changes in GOR and the amount of kerogen. Since the shale consists of plate-like particles, it has vertical transverse isotropy (VTI). Therefore we estimated the seismic velocity and density by using Backus averaging method and analyzed AVO responses based on these estimated properties. The results of analysis showed that the changes in the velocity with the GOR variation are small but the velocity changes with the variation in kerogen amount are relatively larger. In case, GOR 180 (Litre/Litre) which is boundary between heavy oil and light oil, when volume fraction of kerogen increased from 5% to 35%, the P-wave velocity normal to the layering increased 51%. That is, it helps estimating maturity of kerogen through the velocity. Meanwhile, when rates of oil-gas mixture are large, the effect of GOR variation on the velocity change became larger. In case volume fraction of kerogen is 5%, the P-wave velocity normal to the layering was estimated $1.46km/s^2$ in heavy oil (GOR 40) but $1.36km/s^2$ in light oil (GOR 300). The AVO responses analysis showed class 4 regardless of the GOR and amount of kerogen because variation of poisson's ratio is small. Therefore, shale reservoir has possibility to have class 4.

• Journal of computational fluids engineering
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• v.21 no.3
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• pp.31-38
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• 2016

The FDS-HCIB method is expanded to simulate water-oil-air flows around oil booms under relative motion, which is intended to increase the thickness of contained oil. The FDS scheme captures discontinuity in the density field and abrupt change of the tangential velocity across an interface without smearing. The HCIB method handles relative motions of thin oil booms with ease. To validate the developed FDS-HCIB code for water-oil-air flow around a moving body, the computed results are compared with the reported experimental results on the shape, length, and thickness of the oil slicks under towing. It is observed that the increase in pressure field between two barriers lifts the oil slick and the interfacial wave propagates and reflects as one barrier gets closer to the other barrier.

• Membrane Journal
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• v.6 no.2
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• pp.86-95
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• 1996

Rotary disc ultrafiltration module(RDM) was developed for the separation of oil e$$\mu$sions. This module was devised to reduce the gel polarization phenomenon by decoupling the operation pressure and the surface velocity of solution in ultrafiltration(UF) processes. The rotary disc membrane consists of 3mm-thick ABS plate covered with UF membrane (UOP, U.S.A.). When the angular velocity($\omega$) was increased, the pure water flux was slightly decreased due to pressure drop caused by centrifugal force and slip flow at the surface of membrane. The pressure drop was proportional to the square of linear velocity(${\omega}r$). When the angular velocity was changed from 52.36rad/s to 2.62rad/s, the flux decline for 5% cutting oil in one-shaft RDM at $25^{\circ}C$ and 0.1MPa was 30.16%. In the lower concentrations, angular velocity tends to give less effect on the flux. Flux(J; $kg/m^{2} \cdot s$) in a rotating disc module is mainly a function of the bulk concentration($C_{B}$; %), the linear velocity(${\omega}r$; m/s) and the effective transmembrane pressure($\Delta P_{T}$ ; Pa). Using a modified resistance-in-series model, the flux data of cutting oil experiments were fitted to give the following equation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.451-454
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• 2003

The Oil Coolers is very important unit for the stable thermal performance in machine tools, semiconductor equipments and high precision measuring systems. To select a proper oil cooler for the temperature control of core unit in a machine, not only cooling ability but also static and dynamic sensitivity of temperature sensors are considered. In this paper, the relationship between cooling ability and inflow oil temperature is identified. The cooling ability is increased with the increase of inflow oil temperature. The oil temperature control errors of a cooler are influenced by mainly sensitivity of temperature sensors and heating velocity in a machine. The validity of error cause analysis for temperature control is proved by real cooling experiments with inflow and outflow temperature sensors.

• Magazine of the Korean Society of Agricultural Engineers
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• v.18 no.4
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• pp.4259-4264
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• 1976

This paper, is about the test on the operating performance of diesel engine by using of soybean oil which farmers could supply in their farm yard. The diesel engine used is a swirl-chamber type, four stroke cycle with single cylinder, air cooling and its rated horse power is 2 PS per 1300 rpm. Several results obtained are as follows; 1. The starting performance of diesel engine with soybean oil is almost the same as that with light oil. 2. The variation of engine speed according to various engine load is small when soybean oil is used compared with light oil. It is considered that soybean oil is desirable for the purpose of industerial power machine fuel. 3. The specific fuel consumption increases approximately 10 percent high in the condition of rated horse power and maximum horse power and shows less or same during the load test in low velocity, when soybean oil is used 4. Though the brake thermal efficiency in the condition of rated horse power and maximum horse power is inclined to decrease when soybean oil is used compared during the load test in low velocityt shows good inclination.

• Tribology and Lubricants
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• v.34 no.3
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• pp.93-107
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• 2018

The purpose of Part I of this study is to find the potential region of wear scarring on engine journal bearings operating at a constant angular crank shaft velocity under firing conditions. To do this, we calculate the applied loads and eccentricities of a big-end journal bearing installed on a four-stroke and four-cylinder engine at every crank angle. Then, we find potential wear regions, such as a minimum oil film thickness, at every crank angle below most oil film thickness scarring wear (MOFTSW) obtained based on the concept of the centerline average surface roughness. Thus, the wear region is defined as a set of each film thickness below the MOFTSW at every crank angle. In this region, the wear volume changes according to the wear depth and wear angle, depending on the minimum oil film thickness at every crank angle. The total wear volume is the summation during one cycle. Graphical views of the region in the two-dimensional coordinates show the crank angle and bearing angle along the journal center path, indicating the position of the minimum oil film thickness. The results of wear analysis show that the possible wear region is located at a few tens of angles behind the upper center of a big-end bearing at maximum power rpm.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.71-71
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• 2018

Sea pollution accidents have been occurred due to the increase of marine ship traffic. Oil spill from the hull hole induced by tanker collision results in the huge sea pollution. Proper and prompt reaction on such oil spill disaster is needed to minimize the damage. Thru-hull emergency wood plug is typically used to manually close small holes, while it is required to develop some mechanical devices for closing large holes in the hull due to huge fluid pressure. Accurate estimation of oil discharge and velocity from such holes are important to develop proper device to control hull hole damage. High resolution CFD modeling investigation on the configurations of hull hole of 7.5 m initial depth and 30 cm diameter, which was observed in the oil spill accident of the Hebei Sprit off the west coast of Korea in 2007, has been carried out to compute the oil spill velocity distribution in terms of flow depth. Friction loss due to the viscous flow and the discharge coefficient of crude oil with specific gravity SG = 0.85 and viscosity of $4-12cP(mPa{\cdot}s)$ at the temperature of $20^{\circ}C-100^{\circ}C$ are presented in terms of Reynolds number based on the results of high-resolution CFD modeling.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.693-700
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• 2006

The important factor for the development of burner is the achievement of low emissions with maintaining combustibility. In case of maintaining high temperature flame and excess air to increase the combustibility, it is possible to achieve high combustion efficiency, due to the reduction of UHC(unborn hydrocarbon), carbon monoxide and soot. However, it is difficult to reduce the thermal NOx produced in the high temperature flame. To solve this problem, we developed externally oscillated oil burner which is possible for the high efficiency combustion and low NOx emission, simultaneously. The experiment of flame characteristics and NOx reduction were achieved according to the variation of frequency, amplitude and air velocity. Frequency, amplitude and air velocity are the most important parameter. The optimum operating conditions are frequency 1,900 Hz, amplitude 3 $V_{pp.}$ and air velocity 6.8 m/s. Reduction of NOx and CO are 47% and 22%, respectively.

• Journal of ILASS-Korea
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• v.7 no.3
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• pp.38-44
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• 2002

The purpose of this study is to investigate the effect of the volume fraction of water and injection pressure on the spray characteristics of water/oil emulsified fuel injected from the pressure swirl atomizer. The mixture of light oil and water by using impeller mixer was performed. The spray characteristics such as SMD and velocity were measured using PDPA. The injection pressures were 7.5, 100, 200 and $300kgt/cm^2$ and volume fractions of water in emulsified fuel were 0, 10, 20 and 30%, respectively. The measurement sections were at 30, 60 and 90mm from injection nozzle tip. SMD and velocity of emulsified fuel were larger gradually by increasing the volume fraction of water in emulsified fuel. The spray angle was decreased and axial velocity was increased with increase in water content. It was found that the relative SMD ratio was increased more greatly than the relative axial velocity ratio in super critical pressure. The relative SMD ratio was increased and the relative axial velocity ratio was decreased with increase injection pressure at spray downstream.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.3
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• pp.337-349
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• 1996

A study was conducted to find the possible relationship between slip distance and dynamic coefficient of friction (DCOF) through the biomechanical study of slips and falls using a broader variety of floors and levels of slipperiness than those used before. Four different floor surfaces covering the full range of floor slipperiness (with and without on oil contaminant) were prepared for ten subjects with each walking at a fixed velocity. The results showed that slip distance and heel velocity had a decreasing trend while stride length had a increasing trend as DCOF increased. The contaminant effect overpowered floor slipperiness effect because a higher DCOF surface with oil contaminant created longer slip distance than the lower DCOF with dry floor. Normal gait pattern and suggested heel velocity (10 to 20 cm/sec) were seen on dry floors but abnormally longer stride length and 5 to 10 times faster heel velocity were found an oily floors. In other words, faster heel velocity (greater than 10 to 20 cm/sec) is recommended to measure DCOF on oily floors because the assumption of normal gait was no longer valid.