• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.272-277
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• 2000

The flow computer named Kogas I has been developed for measuring high flow natural gas. The developed model is classified as individual type in order that one flow computer covers one metering line. Nearly all of the functions are adopted similar to the foreign, commercial flow computer, and the merit of this flow computer is being able to apply for both orifice and turbine meters. The performance has been verified through the field test for 2 years.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.89-94
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• 2008

Differential pressure flow meters which have a shape of triangular separate bar(TSB) were tested for investigating the flow rate characteristics of the flow meters with varying the temperature of the gas flow. Three kinds of the triangular separate bar flow meters whose aerodynamic angles are different one another are used. The mass flow rate of the flow meters are evaluated using a non-dimensional parameter which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters, and atmospheric pressure. A burner system which is similar to gas turbine was used for raising the gas flow temperature. The burner system was operated with varying the air/fuel ratio by controlling both the fuel injection rate from the fuel nozzle and air flow rate from a blower. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter was obtained. The empirical correlation showed linear relationship between the mass flow rate and the non-dimensional parameter H. Also, the mass flow rate characteristics at the TSB flow meter was affected by the gas temperature.

• Journal of the Korean Society of Visualization
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• v.7 no.2
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• pp.64-71
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• 2010

The flow and noise characteristics of wake behind wind-turbine blades have been investigated experimentally using a two-frame particle image velocimetry (PIV) technique. Experiments were carried out in a POSTECH subsonic large wind-tunnel ($1.8^W{\times}1.5^H{\times}4.3^L\;m^3$) with KBP-750D (3-blade type) wind-turbine model at a freestream velocity of $U_o\;=\;15\;m/s$ and a tip speed ratio $\lambda\;=\;6.14$ (2933 rpm). The wind-turbine blades are connected to an AC servo motor, brake, encoder and torque meter to control the rotational speed and to extract a synchronization signal for PIV measurements. The wake flow was measured at four azimuth angles ($\phi\;=\;0^{\circ}$, $30^{\circ}$, $60^{\circ}$ and $90^{\circ}$) of the wind-turbine blade. The dominant flow structure of the wake is large-scale tip vortices. The turbulent statistics such as turbulent intensity are weakened as the flow goes downstream due to turbulent dissipation. The dominant peak frequency of the noise signal is identical to the rotation frequency of blades. The noise seems to be mainly induced by the tip vortices.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.158-165
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• 2005

KOGAS(Korea Gas Corporation) has about a hundred of local stations to supply natural gas to the city gas companies and the power stations. As some severe flow fluctuation phenomena are observed in several governor stations, the investigation about the reasons and factors which are relating to flow fluctuation has been started. Some field surveys hav been carried out and experimental studies have been performed to find the fluctuation mechanism. As a result, it is found that the flow fluctuation is related with the length of straight pipe in front of the meter, the size of the header pipe and the variation of demand at the city gas company and the power station. Furthermore. it is also proved that both the length of the transmitter cable and the status of the coating of signal transmission cable do not affect flow fluctuation, but the measurement range of the differential pressure transmitter influences flow fluctuation. On the other hand, as the averaging the flow fluctuation is converged to less than 0.1 % in almost all of the cases, it is concluded that the quantity of flow fluctuation do not relates to metering accuracy directly.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.9
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• pp.712-719
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• 2008

Light Oil Flow Standard System(LOFSS), as a national oil flow standard system, in Korea Research Institute of Standards and Science(KRISS) was developed for oil flowmeter calibration, and the expanded uncertainty of flow quantity determination was estimated within 0.04 %. In order to improve the reliability of the LOFSS measurement, a proficiency test was carried out in the flow range of 20 and $240\;m^3/h$ (Reynolds number $20,000{\sim}900,000$). A turbine flowmeter was used as a transfer package in round robin test. The water flow standard system of KRISS, the pipe prover of the national calibration and test organization and the master meter calibrator of the turbine flowmeter supplier, which used the different working fluid respectively, were compared with the turbine flowmeter measurement. The maximum difference of measurement was 0.15 % between the LOFSS and the pipe prover. The En numbers of the each system measurement were evaluated at the same Reynolds number. It was found that the En numbers were less than 1 in the comparison, which means the procedures of the uncertainty estimation of the each calibrators were reasonable and reliable.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.453-460
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• 2000

A test rig is developed for performance test of 1 stage axial-type turbine which is designed by meanline analysis, streamline curvature method, and blade design method using configuration parameters. The purpose of this study is to find the best configuration parameters for designing a high efficiency axial-type turbine blade. To measure the efficiency of turbine stage, a dynamo-meter is installed. Two different stators which are manufactured as an integrated type are developed, and a rotor blade and 5 sets disc are developed for setting different stagger angle. The tip and hub diameters of the test turbine are 300 and 206.4mm, respectively. The rotating speed is 1800RPM, and the extracted power is 2.5kW. Flow coefficient is 1.68 and the reaction factor at meanline is 0.373. The number of stator and rotor of test turbine are 31 and 41, respectively. The Mach number of stator exit flow near hub is 0.164.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.205.1-205.1
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• 2011

This study concerns a low head and kaplan turbine efficiency measurement using the acoustic scintillation flow meter(ASFM). The ASFM is one of absolute discharge measurement methods because it measures velocity-area of discharge with couples of transducers. This study shows that the highest efficiency of turbine is 87.7% and the efficiency is 85.8% in the rated output(600kW). The test result is reliable because the efficiency trend from this test is similar to the result of index test conducted in 1986. In this paper, the principle, measurement methods, application and test procedures of the test are discussed.

• Journal of the Korean Professional Engineers Association
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• v.15 no.1
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• pp.32-35
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• 1982

The sudden shock of repeated oil crisis and the subsequent violent increases in petroleum prices have given rise to an intensive worldwide effort to develop alternate sources of clean energy. Against this background, a great deal of attention has recently come to be focused on mini-scale hydroelectric power turbine generation. There is now a strong demand for the development of a hydroelectric generator suitable for generating power on a small scale and copable of overcoming the high per kilowatt cost of conventional one's then Francis turbine. Hence was accordingly developed the "Cross flowturbine generator" of 1000kw and less, which we call. This mimi-scale water turbine is reliably and easily handled and also can be economicaly manufactored in a range with effective head of over 3meter's a flow rate of minimum 30 liter per sec and an output of below 1000kw good's.kw good's.

• Archives of design research
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• v.17 no.2
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• pp.351-362
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• 2004

Generally, they respond to a phenomenon, with their any way, which they have looked at in their surroundings, and also put into their action successively and variously according as what it is. A person who has not so much problems in experiential education added to mental and physical ability prefers controlling his manner by himself as seeing, listening and feeling to being cured it by other physical support. Meanwhile, even though there are tools that we use conveniently in everyday life, it is sometimes required that user is able to control his action by himself with a certain interactive function to deal with a accidental situation. For example, in the home, when they were cooking, washing dishes and taking a bath they would not often control their minds on how to act about flowing water through the faucet going back and forth between saving and easygoing. By reasons of those statements, the project has been studied to propose the new conceptual faucet which digital technology is applied to, for recognizing the volume of water flowed through water pipe as counting it with built-in flow meter, and then saving water as controling the water-flow with faucet lever. It means that homemakers can observe the flow rate of water from the faucet placed in front of the sink in kitchen and control it right away for saving water. For studying this project, the kinds and features of the various flow-meters that measure the volume of water-flow were researched and analyzed for taking a reasonable type to the new ideal faucet. According to this analyzing, turbine-flow-meter was selected as appropriate form for the digital display-built-in faucet that would be presented in this project. As the next step, the basic structure was created for developing a new conceptual faucet. Finally two models have been presented through several steps for making the suitable shape to the new style faucet.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.36-46
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• 2000

The performance improvement and emission reduction in a turbocharged D.I. diesel engine was studied experimentally in this paper. The system of intake port, fuel injection and turbochager are very important factors which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. Through these experiments it can be expected to meet performance and emission by optimizing the main parameters; the swirl ratio of intake port, fuel injection system and turbocharger. The swirl ratio of intake port was modified by hand-working and measured by impulse swirl meter. Through this steady flow test, we knew that the increase of swirl ratio is decreasing the mean flow coefficient, whereas the gulf factor is increasing. And the optimum results of engine performance and emission are as follows; the swirl ratio is 2.43, injection timing is BTDC 13。 CA, compression ratio is 16, combustion bowl is re-entrant 5$^{\circ}$, nozzle hole diameter is $\Phi$0.28＊6, turbocharger is GT40 model which are compressor A/R 0.58 AND turbine A/R 1.19.