• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.1
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• pp.1-8
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• 2020

In this study, a configuration design of a CH₄/LOx small rocket engine was made and test system was established for the performance evaluation. A coaxial swirl injector was chosen because of its remarkable atomization performance and low combustion instability. Three aspect ratios for the combustion chamber configuration, i.e., 1.5, 1.8, and 2.1 were also set for the comparison of the combustion efficiency. The reliability of the thrust measurement rig was enhanced by pre-and post-calibration process. From the preliminary ground hot-firing test, the measured thrust and specific impulse values were 89.2 N and 181.8 s, respectively, which were 21.6% lower than the ideal values. In addition, the efficiency of characteristic velocity was measured as 84.2%.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.265-266
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• 2010

This paper propose the test method for performance of myoelectric hand prosthesis(MHP) according to myoelectric signal generated in the human muscle. The MHP consists of a mechanical hand, a surface myoelectric sensor(SMES) for measuring myoelectric signal, a control system and a charging battery. The propose test method is proved the reliability of MHP.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.9
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• pp.903-909
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• 2007

A fatigue capsule is one of the special capsules to investigate the fatigue characteristics of the nuclear materials during an irradiation test in a research reactor, HANARO. In this study, the performance test and the preliminary fatigue test results by using a cyclic load device newly developed for a fatigue capsule are described. In order to obtain the characteristics such as a realization and a controllability of the periodic wave shape and the relationship between the pressure and the load, a spring and rigid bar specimens are used. The fatigue test for the 316L stainless steel specimen with 1.8mm in diameter and 12.5mm in gage length is also performed under the same conditions as the temperature($550^{\circ}C$) of the specimen during irradiation tests. As a result of the test, the fracture of the specimen occurs at a total of 70,120 cycles(about 12 days), and the displacement in this case is 2.02 mm. It is expected that these results will be used for determining test conditions and a comparison of the in-pile fatigue test results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.295-298
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• 2001

This paper presents mechanical properties and weatherability of FRP pole used for a distribution line about high strength and good insulation properties. The experiment strength obtained in cantilever beam test are comparable to ES standards. The environmental factors, such as elevated temperatures, high humidity, and corrosive fluids, and ultraviolet(UV) rays, influence on the performance of Polymeric matrix composite.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.2
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• pp.177-187
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• 2016

To evaluate the tractive performance of tracked trencher on seafloor surface, a new shear stress-displacement empirical model was proposed for saturated soft-plastic soil (SSP model). To validate the SSP model, a test platform, where track segment shear test can be performed in seafloor soil simulacrum (bentonite water mixture), was built. Series shear tests were carried out. Test results indicate that the SSP model can describe the mechanical behavior of track segment with good approximation in seafloor soil simulacrum. Through analyzing the main external forces applied to seafloor tracked trencher during the uniform linear trenching process, a drawbar pull prediction model was deduced with the SSP model. A tracked walking mechanism of the seafloor tracked trencher prototype was built, and verification tests were carried out. Test results indicate that this prediction model was feasible and effective; moreover, from another side, this conclusion also proved that the SSP model was effective.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.19-25
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• 2008

Selective Catalytic Reduction is effective in the reduction of NOx emission. This research focused to evaluate the performance of a urea-SCR system and was conducted in two procedures. One is SCR reactor test using model gas in order to provide an optimal injection condition itself. In this step, some parametric study on emission temperature, space velocity, aspect ratio and the formation of urea spray were made by using flow visualization and Computation Fluid Dynamics techniques. The basic simulation results contributed in determining the layout for an actual engine test. The other is an engine performance and emission test. The urea injector was placed at the opposite direction of exhaust gases emitted into an exhaust duct and an optimal amount of a reducing agent is estimated accurately under different engine loads and speeds. Furthermore, the variation of NOx emission and applied amount of urea was investigated in terms of modes under the condition of with and without SCR, and other emissions such as PM, CO and NMHC were evaluated quantitatively as well. This research may provide fundamental data for the practical use of urea-SCR in future.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.364-369
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• 2007

A system heat pump provides the benefits of comfort, energy conservation and easy maintenance. Recently, the system heat pump has been employed in small and medium-sized buildings. However, the performance data and control algorithm for system heat pump are limited in literature due to complicated system parameters and operating conditions. In the present study, the performance of a system heat pump with two indoor unit is measured by varying indoor loads, EEV opening, and compressor speed. In addition, the integral optimum regulator which includes MIMO control algorithm is proposed. The capacity modulation and optimum capacity for each indoor unit can be adjusted by utilizing the EEVs opening and compressor speed. The proposed scheme shows appropriate control performance at test conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.804-808
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• 2005

A pneumatic tire is made up of many flexible filaments of high modulus cord of natural textile, synthetic polymer, glass fiber, or fine hard drawn steel embedded in and bonded to a matrix of low modulus polymetric material. Adhesion property of these materials is very important in tire durability safety because belt-leaving-belt tread separation reduces the ability of a driver to control a vehicle, whether or not the separation is accompanied by a loss of air. In this study adhesion test of carcass-belt-tread is conducted on material properties of 5 PCR tire model, which are on sale in domestic market and analyzed adhesion properties. For those tire models FMVSS 109 indoor high speed durability test is conducted to analyze the correlation between adhesion force and high speed performance of tires and found the correlation between the two test results.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1431-1440
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• 1993

This paper presents a new NC machine performance test and calibration system. In order to measure NC machine erros in simpler, and less time-comsuming way, some indirect measuring systems such as circular disk system and double ball bar system have been developed instead of laser interferometer. But these indirect measuring systems have shown their limits in identifying each of NC machine error sources in absolute numerical value. Therefore, we developed an unique NC machine error measurement system which provides a simple measuring process like other conventional indirect methods and still can indentify each of NC machine error sources in absolute numerical value.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.11
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• pp.1315-1321
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• 2004

Quantitative performance test on the conventional 2D-PIV and the hybrid angular 3D-PIV(Stereoscopic PIV) was carried out. LES Data sets on an impinging jet which are provided on the webpage(http://www.vsj.or.jp/piv) for the PIV Standard Project were used for the generation of virtual images. The generated virtual images were used for the 2D-PIV and 3D-PIV measurements test. It has been shown that the results obtained by 2D-PIV on average values are slightly closer to the LES data than those obtained by 3D-PIV, but the turbulent properties obtained by 2D-PIV are largely underestimated than those obtained by 3D-PIV.