• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.23-28
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• 1996

The potential for the RELAP5/MOD3.2 was assessed for the loss-of-RHR event during the mid-loop operation and the predictability of major thermal-hydraulic phenomena was also evaluated for the long term transient. The analysis results of the typical two cases(cold leg opening case and pressurizer opening case) were compared with experimental data which was conducted at ROSA-IV/LSTF in Japan. As a result, it was shown that tile code was capable of simulating the thermal-hydraulic transport process with appropriate time step during the reduced inventory operation with the loss-of- RHR system.

• Nuclear Engineering and Technology
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• v.31 no.1
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• pp.88-103
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• 1999

The purposes of this study are to understand the severe accident phenomena, to establish the simulation method for the experimental test, and to assess the current models in MELCOR for future improvement. This paper presents the results of the PHEBUS FPT1 post test analysis using MELCOR computer code, version 1.8.4. The entire PHEBUS facility has been modeled; the core, the primary circuit including the steam generator, and the containment vessel. Both the thermal hydraulic and the fission product behavior have been investigated. The code simulation results of the thermal hydraulic behavior show good agreement with the experimental data, The fission product release and transport are calculated using the CORSOR models in MELCOR code and the results will be compared with the experiment when the experimental data are available.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.251-261
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• 1997

A package to transport the high level radioactive materials is required to withstand the hypothetical accident conditions as well as normal transport conditions according to IAEA standards and domestic regulations. The regulations require that the package should maintain the shielding, thermal and structural integrities to release no radioactive material. In general, safety evaluation of packages is performed by experimental methods using scale model and/or analytical methods using computer codes. This paper presents the safety evaluation of package to transport the radioisotopes produced in the HANARO to the radioisotope production facility. Radiation shielding, thermal and structural analyses were peformed using the computer codes. It has been verified that the package is safe under hypothetical accident conditions as well as normal transport conditions.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.465-470
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• 2006

An experimental investigation is carried out to study 2-phase vertically upward hydraulic transport of solid particles by water and non-Newtonian fluids in a slim hole concentric annulus with rotation of the inner cylinder. Rheology of particulate suspensions in viscoelastic fluids is of importance in many applications such as particle removal from surfaces, transport of proppants in fractured reservoir and cleaning of drilling holes, etc. In this study a clear acrylic pipe was used in order to observe the movement of solid particles. Annular fluid velocities varied from 0.2 m/s to 3.0 m/s. Pressure drops and average flow rate and particle rising velocity are measured. For both water and 0.2% CMC solutions, the higher the concentration of the solid particles is, the larger the pressure gradients become.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.148.3-148
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• 2001

This paper deals with a problem of decreasing the airspeed and the altitude of a transport aircraft using thrust only. Such a situation can occur, if the aircraft loses all hydraulic power that drives the control surfaces. A controller for flight path angle control is designed using the model following servo control method, which is a PI-type optimal regulator. For computer simulation, a simulation model that covers a range of flight envelope is made using given linear models and trim points at some flight conditions. Nondimensional aerodynamic coefficients, derivatives and trim points that are not at the given trim points are computed by linear interpolation. The model is effective in simulation where the trim point varies. Simulation using ...

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.2
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• pp.129-135
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• 1990

A two-dimensional nonlinear tidal model of the Asan Bay has been formulated to examine the tide and related hydraulic phenomena. The $M_2$ tidal regime was first computed using the model and the model also was to derive the maximum bed stress and transport potential in the region. Preliminary assessment of relation between sediment transport and the maximum bed stress distribution determined from the model are described.

• Advances in biomechanics and applications
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• v.1 no.4
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• pp.227-237
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• 2014

The in vitro construction of osteo-articular large implants combining biomaterials and cells is of great interest since these tissues have limited regeneration capability. But the development of such organoids is particularly challenging, especially in the later time of the culture, when the extracellular matrix has almost filled the initial porous network. The fluid flow needed to efficiently perfuse the sample can then not be achieved using only the hydraulic driving force. In this paper, we investigate the interest of using an electric field to promote mass transport through the scaffold at the late stage of the culture. Based on the resolution of the electrokinetics equations, this study provides an estimation of the necessary electric driving force to reach a sufficient oxygen perfusion through the sample, thus analyzing the feasibility of this concept. The possible consequences of such electric fields on cellular activities are then discussed.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.369-372
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• 2008

An experimental study is carried out to study two-phase vertically upward hydraulic transport of solid particles by water in a vertical and inclined (0${\sim}$60 degree) concentric annulus with rotation of the inner cylinder. Rheology of particulate suspensions in shear-thinning fluids is of importance in many applications such as particle removal from surfaces, transport of proppants in fractured reservoir and cleaning of drilling holes, and so on. Annular fluid velocities varied from 0.2 m/s to 1.5 m/s for the actual drilling operational condition. Macroscopic behavior of solid particles, averaged flow rate, and particle rising velocity are observed. Main parameters considered in this study were radius ratio, inner-pipe rotary speed, fluid flow regime, and particle injection rate. For both water and CMC solutions, the higher the concentration of the solid particles is, the larger the pressure gradients become

• Journal of Mechanical Science and Technology
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• v.16 no.4
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• pp.549-556
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• 2002

An investigation on the fully developed heat transfer and friction factor characteristics has been made in rectangular ducts with one-side roughened by five different shapes. The effects of rib shape geometries as well as Reynolds numbers are examined. The rib height-to-duct hydraulic diameter, pitch-to-height ratio, and aspect ratio of channel width to height are fixed at e/De=0.0476, P/e=8, and W/H=2.33, respectively. To understand the characteristics of heat transfer enhancements, the friction factors are also measured. The data indicates that the triangular type rib has a substantially higher heat transfer performance than any other ones.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.9
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• pp.823-829
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• 2012

An excitation table is commonly used for vibration and ride tests for parts or assemblies of automobiles, aircrafts, or other heavy systems. The authors have analyzed several kinematic properties of an excitation table that is under development for heavy transport vehicles. It consists of one table and 7 linear hydraulic actuators. The authors have performed mobility analysis, inverse kinematics, forward kinematics, and singularity analysis. Especially, we have proposed a fast forward kinematic solution considering the limited motion of the excitation table. On the assumption that the motion variables such as rotation angles and displacements are small, the forward kinematic problem is converted to the observer problem of a linear system. This provides a fast solution. Also we have verified that there are no singularity points in the working range by numerical analysis.