• Journal of Aerospace System Engineering
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• v.6 no.2
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• pp.35-41
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• 2012

A reciprocating engine installed on a normal category airplane shall be effectively cooled by air flown through the engine compartment. A airplane powerplant designer has to design cooling air inlets, baffles, seals, and outlets to maintain cylinder head temperatures and oil temperature under the limits, and show compliance with appropriate airworthiness standard. In this study, cooling designs of the installed engine and compliance requirements applicable to the cooling designs were reviewed, and engine cooling flight test results were evaluated for design changes. Engine cooling certification test will be conducted in a next step.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.2
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• pp.236-243
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• 2016

This paper presents a simple thermo-physical model of reciprocating compressors for household refrigerator-freezers. The compressor model has been developed based on thermodynamic principles and large data sets from the compressor calorimeter tests. The input data are compressor geometry (displacement and clearance volume), compressor speed, suction pressure and temperature, discharge pressure, and ambient temperature. The model can estimate mass flow rate and compressor power consumption within 3.0% accuracy, which is not much larger than measurement errors associated with calorimeter testing under ideal conditions.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.656-661
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• 2003

Modem reciprocating air compressors have tendency to a multi-stage W-type or V-type cylinder arrangement for the purpose of high outlet pressure, compactness and low vibration and noise. A valid counter weight calculation method using the complex expression is proposed for reducing the inertia forces of the compressor. Counter weight removes only 1st forward whirl component. Counter weight formulations are applied to the six various compressor structures which are (a) 1 cylinder single-throw crank shaft, (b) 2 cylinder single-throw crank shaft (c) 2 cylinder double-throw clank shaft, (d) 3 cylinder single-throw crank shaft, (e) 4 cylinder single-throw crank shaft and (f) 4 cylinder double-throw crank shaft. The improvement of performance is verified through available vibration test.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.96-99
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• 2001

The fatigue life of support bearings is one of the most critical factors for the performance of a control rod driving mechanism. They are operated at high temperature and high pressure and especially lubricated with dramatically low viscosity water. The support bearing is made of standardized 440C stainless steel, and it supports thrust load including the weight of the driving system and external force. Friction and wear characteristics of this material operating under severe lubrication condition is not well known yet, although it is expected to be changed with respect to temperature and boundary pressure. So the friction characteristics are investigated in sliding conditions using the reciprocating tribometer which can simulate the operating conditions. Highly purified water is used as lubricant, and the water is heated up and pressurized. Friction farce on the reciprocating specimens is monitored by the load cells. The results of the experiments are presented in this paper.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.2
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• pp.161-167
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• 2005

The improvements of the propulsive engine efficiencies could reduce the fuel consumption. Therefore. for a marine main diesel engine the substantial increase of stroke bore ratio. so that the engine speed can be significantly reduced in order to increase the Propulsive efficiency. As a typical example. a Sulzer RTA 60C engine has acylinder diameter of 600 mm and each cylinder is capable of delivering 2.369 kW in the speed range 91-114 rpm. In order to Provide basic data for thermal system of marine engine. this work performs an experimental study of heat transfer in a square channel with one rib-roughened wall under sin91e mode of reciprocating oscillation. A selection of heat transfer measurements illustrates the manner by which the reciprocating channel with two opposite heating walls has the higher heat transfer Performance than with four heating wall.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.7
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• pp.640-644
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• 2013

The present study provides the characteristics of friction noise under reciprocating sliding. The friction contact is generated between the aluminum plate and plastic, which results in friction noise. The experimental results reveal that the friction noise under reciprocating sliding can be produced as the friction coefficient increases. It is also shown that the vibration modes of the pin with dominant deflection in the sliding direction is participated on the friction noise.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.10
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• pp.1380-1391
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• 1997

A 150 m$^{3}$/hr, 30 kg/cm$^{2}$, air-cooled 3-stage reciprocating air compressor is designed to be used in starting large diesel engines. A basic design procedure is presented to meet the targeted pressure and flow rate, and especially the volumetric efficiency. Temperature and stress analyses of the cylinder are performed using FEM modelings. The dynamics of valve system is analyzed and stress at the valve seat due to valve impact is evaluated. To reduce friction loss and wear at the compressor engine system, tribological design practices are suggested. Fin-type coolers are designed to dissipate generated compression heat at each stage. Finally, a prototype is manufactured and performance test is carried out utilizing an air tank. Performance results are compared to the design targets, other foreign specifications, and some quality standards.

• Tribology and Lubricants
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• v.39 no.6
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• pp.228-234
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• 2023

In this study, reciprocating wear tests are performed on AISI 52100 bearing steel to investigate its tribological behavior in a hexagonal boron nitride (h-BN) water solution. The h-BN-based aqueous lubricant is prepared using an atoxic procedure called ultrasonic sonication in pure water. Ball-on-flat reciprocating sliding experiments are conducted, where the ball is slewed on a fixed flat at 50-㎛ displacement. The lubricating behavior of h-BN is compared with that of deionized (DI) water. Results show that the friction coefficient is higher in h-BN testing than that in DI tests, but the results are equalized as the friction coefficient reaches a stable level. Scanning electron microscopic images reveal significant material loss in the center and mild abrasion on the edge of the wear scar in h-BN tests. However, these effects are minor in DI water situations. The results of energy-dispersive X-ray spectroscopy show that considerable oxidation occurs in the central zone of the wear scar in h-BN cases with strong adhesion and material removal. These findings reveal the importance of determining ideal circumstances that can tolerate material friction and wear.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.344.1-344
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• 2002

A newly devised linear flexures bearing (KIMM-LFB) for reciprocating machines is disclosed having improved reliability for long lift. KIMM-LFB is an integrated device comprising a axially moving diaphragm with circumferentially arranged arc-shaped flexure blades secured between rim and hub spacers, which turn out to have higher radial stiffness and lower Von-Mises peak stresses than the one with circumferential tangent cantilever flexure blades. (omitted)

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.61-63
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• 2009

This paper design a rotor shape of a BLDC motor used for reciprocating compressor. Demagnetization analysis of a basic model is performed by 2D finite element method. This type improved demagnetization characteristics and showed good performance to resist partial demagnetization of ferrite magnet.