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Chang, Seok-Kyu;Euh, Dong-Jin;Choi, Hae Seob;Kim, Hyungmo;Choi, Sun Rock;Lee, Hyeong-Yeon
- Nuclear Engineering and Technology
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- v.48 no.2
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- pp.376-385
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- 2016
A hexagonally arrayed 37-pin wire-wrapped rod bundle has been chosen to provide the experimental data of the pressure loss and flow rate in subchannels for validating subchannel analysis codes for the sodium-cooled fast reactor core thermal/hydraulic design. The iso-kinetic sampling method has been adopted to measure the flow rate at subchannels, and newly designed sampling probes which preserve the flow area of subchannels have been devised. Experimental tests have been performed at 20-115% of the nominal flow rate and $60^{\circ}C$ (equivalent to Re ~ 37,100) at the inlet of the test rig. The pressure loss data in three measured subchannels were almost identical regardless of the subchannel locations. The flow rate at each type of subchannel was identified and the flow split factors were evaluated from the measured data. The predicted correlations and the computational fluid dynamics results agreed reasonably with the experimental data.
https://doi.org/10.1016/j.net.2015.12.013 인용 PDF KSCI

박인준;박양수;김수일
- Proceedings of the Korean Geotechical Society Conference
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- 2000.03b
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- pp.183-190
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- 2000
Effective range of Hydraulic Hammer Compaction was studied by numerical analysis instead of empirical method. Numerical analyses were carried out with commercial FEM code, ABAQUS, and verified by comparing the numerical results with field tests of Hydraulic Hammer Compaction. Most of material properties were evaluated by data from laboratory and in-situ tests. Vertical effective range was estimated by distribution curve of plastic strain energy dissipated through soil layers under dynamic load and these results were in good agreement with field tests. Based on verification, the effects of governing properties of Hydraulic Hammer Compaction such as number of hit can be determined by numerical analyses. In addition, vertical effective range can also be determined by Menard's empirical equation using the external work at converging time of plastic strain energy in numerical analysis. This implies that the minimum energy of Hydraulic Hammer Compaction for improvement can be determined by Menard's equation.
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Choi, Soon-Woo;Huh, Jun-Young
- Transactions of The Korea Fluid Power Systems Society
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- v.7 no.2
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- pp.19-26
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- 2010
The typical trunk lid system for vehicle is composed of a hinge having 4-bar link and gas lifter. Here, the energy regenerative brake of hydraulic driven systems is applied to the tail gate system for vehicle and removed the gas lifter. The new tail gate system is composed of a hydraulic pump by electric motor, a hydraulic motor, four check valves, an accumulator, a relief valve and a directional control valve. The dynamic characteristics of the hydraulic motor system, such as the surge pressure and response time, are investigated in both brake action and acceleration action. The capacity selection method of accumulator by mathematical model is based upon trial and error approach and computer simulation by AMEsim software is carried out.
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Lee, Min-Su;Ahn, Kyoung-Kwan;Cho, Yong-Rae;Jo, Woo-Keun;Hung, Ho Triet
- Proceedings of the KSME Conference
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- 2008.11a
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- pp.917-922
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- 2008
In order to reduce energy consumption, secondary controlled system has been applied to many types of equipments. In lifting equipments or press machines using hydraulic cylinder, a hydraulic transformer is used as a control component instead of a valve for motion control and a component for recovering potential energy of load. The transformer is combination of a variable displacement pump/motor as a secondary controlled element and a fixed displacement pump/motor. Based on the nominal model derived from mathematical model, the feedback type two-degree-of-freedom controller is designed and implemented. From simulation results, the disturbances including nonlinear friction torque, leakage flow and load force can be compensated and good positioning accuracy is obtained. It show that the proposed controller is effective.
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