• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.445-450
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• 2004

Recently, many studies have been performed and good results have been reported in literature on the prediction of the brake disk temperature. However, study on the brake fluid temperature is rarely found despite of its importance. In this study, brake fluid temperature is predicted according to material property of brake piston. For the analysis, a typical disk-pad brake system is modeled including the brake disk, pad, caliper, piston and brake fluid. Vehicle deceleration, weight distribution by deceleration, disc-pad heat division and the cooling of brake components are considered in the analysis of heat transfer. Unsteady-state temperature distribution are analyzed by using the finite element method and numerical results are compared with the vehicle test data

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.753-758
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• 2000

Heat engine and fluid machinery in the plant have to linked with various ducts network and the corresponding design have to be concerned about effectiveness and stability of system of plant. To optimum control and design system concerning stability, economization, operating effectiveness we have to exact analysis flow properties of a duct applying to fluid machinery, heat exchanger, cooling machine, air conditioning equipment. therefore, it is necessary to research the duct, heat transfer equipment, for increasing overall effectiveness of air conditioning system by suggesting basic data of the duct resulting from organic research. So we can contribute to technical development of the duct. In case of speeding up the flow rate of the duct, lots of wave velocity components are occurred the value of boundary layer resulting from developing the boundary layer at both walls of duct.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.2
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• pp.9-16
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• 2004

Because a generated heat during grinding operation makes a serious deformation on a ground surface as a convex form, a real depth of cut in deformed zone has larger than an ideal depth of cut. Consequently, the ground surface has a geometric error as a concave form after cooling the workpiece. In this study, the force and the geometric error of surface grinding were examined. From evaluating magnitude and mode of the geometric error according to grinding conditions, an optimal grinding condition was proposed to minimize the geometric error. In addiction the relationship between the geometric error and the grinding force was found out. Due to least square regression it was able to predict the geometric error by using the grinding force.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.7
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• pp.549-556
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• 1989

Radiation induced current of the insulating oil used for X-ray tube housing was investigated in this paper. The X-ray induced current increased in proportion to the X-ray intensity and X-ray wave length and was greatly affected by the temperature of the insulating oil and the gap length` however, the current was not varied by the amount of the X-ray absorbed. The results suggest that one must consider the following problems as important factors for X-ray machine design and normal operation: cooling system of the X-ray tube housing, X-ray intensity, increasing temperature due to continuous operation, years used, and oil exchange and management.

• Journal of the Korean Home Economics Association
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• v.20 no.2
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• pp.65-71
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• 1982

Comfort concept of heating and cooling between body and environment is modified by the clothing. So were can say the clothing is one of the environment. To maintain“pleasantness”, clothing must have the elements of comfort and function. This study carried out for the 1st step to describe the relation between clothing and the human body I aspect to the emvironmental elements of temperature and working part of the body. Observations of skin temperature were taken on young adults female subjects in training wear and the skin temperature was measured onto 9 points of the body while taking part in two physical exercise, with Rawing machine and Bicycle ergometer. The results obtained are as follows; 1. The skin temperature after physical exercise is lower than that after repose. 2. After physical exercise of the lower part of the body, the skin temperature is less than that after physical exercise of the upper part of the body. 3. After physical exercise of the upper part of the body, skin temperature of the lower part of the body rises a little, and vice versa.

• Journal of Powder Materials
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• v.10 no.3
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• pp.157-160
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• 2003

Phase contents and elemental composition of ultradispersed powders obtained by the electrical explosion of tin-leadalloy powders are investigated. It is demonstrated that during the explosion and subsequent cooling, surface layers of powder particles are enriched in lead compared to the initial alloy. The thermal stability of powders oxidizing in air is also investigated.

• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.5
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• pp.509-522
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• 1998

An experimental investigation is reported on the heat transfer coefficient from a rotating flat plate in a round turbulent normally impinging water jet. Tests were conducted over a range of jet flow rates, rotational speeds, jet radial posetions with various combinations of three jet nozzle diameter. Dimensionless correlation of average Nusselt number for laminar and turbulent flow is given in terms of jet and rotational Reynolds numbers, dimensionless jet radial position. We suggested various effective promotion methods according to heat transfer characteristics and aspects. The data presented herein will serve as a first step toward providing the information necessary to optimize in rational manner the cooling requirement of impingement cooled rotating machine components.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1092-1098
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• 2004

Today the demand of the optical communication components has been increased. Zirconia Ferrule has become the one of the most important elements because it determines transmission efficiency and quality of information in the optical communication system. Grinding is the major process in the ferrule manufacturing process which require high processing precision. In this reseach, specially designed spindle, chucking system, loading & unloading system and cooling system, as a supporting experimental equipment for development of an Intelligent Coaxial Grinding System (ICGS) for Zirconia Ferrule processing, is developed. We are also analized the adaptability of ICGS in practical use, through the way of evaluation for the performance of the each systems above.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.6
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• pp.45-51
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• 2005

Braking performance of a vehicle can be significantly affected by the temperature increment in the brake system. Therefore, the important problem in brake system is to reduce the thermal effect by friction heat. Recently, many studies have been performed and good results have been reported on the prediction of the brake disk temperature. However, the study on the pad, piston and brake fluid temperature is rarely found despite of its importance. In this study, the temperature distribution of the disc brake system is studied according to the material properties of brake piston. Vehicle deceleration, weight distribution by deceleration, disc-pad heat division and the cooling of brake components are considered in the analysis of heat transfer. Unsteady state temperature distributions are analyzed by using the finite element method and the numerical results are compared with the experimental data.