• Journal of Power System Engineering
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• v.6 no.1
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• pp.36-42
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• 2002

Two-dimensional natural convection in an inclined open cavity with bottom heated, two side insulated and the top open was investigated using PIV(Particle-Image-Velocimetry) measurement. Experimental results are presented for Prandtl number, Pr=6.62, cavity aspect ratio, A=1.0, Rayleigh number from $1.294{\times}10^6\;to\;3.8841{\times}10 ^6$, and inclination angles, ${\alpha}=0$, 30 and 60 deg to the horizontal. It was found that the fluid rises along both side walls in the boundary layer region at ${\alpha}=0\;deg$, and the inclination of the cavity induced flow entrainment. The experimental results are in good agreement with the numerical results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.773-776
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• 2005

An Experiment was carried out to study deburring in frilling hole on the Inclined exit surface. Two different deburring tools, exit surface angles, materials and cutting conditions were selected to check their performance using CNC machining center. In deburring operation, there are not only flat exit surfaces but also inclined exit surfaces which is described as inclination angle. Inclination of exit surface causes a quite different burr formation when comparing with flat surface. Deburring characteristics are analyzed according to the deburring tools and cutting conditions. Several strategies for a effective deburring on inclined exit surface were proposed.

• Journal of the Korean Solar Energy Society
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• v.30 no.4
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• pp.43-48
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• 2010

The performance of photovoltaic systems could be affected by various factors including installing conditions of modules, and their own efficiencies of solar cells and inverters. The installing conditions of a photovoltaic system including array types, tilting angles, azimuth, locations, quantities of sunshine, optimum angles of inclination and separated distance are analyzed using the SolarPro & Minitep SW simulation program, inorder to set up the installing conditions for improving system performance. The result from the simulation of the 500kWp PV system of Kochang with optimal installing conditions compared with normal conditions shows that the capacity factor has been increased from 11.02% to 12.06%.

• Journal of Energy Engineering
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• v.18 no.1
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• pp.1-8
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• 2009

This paper reports the experimental study of natural convection heat transfer with $Al_2O_3$-water nanofluid. Experimental apparatus was a cylindrical enclosure with adjustable fluid layer thickness, and the aspect ratio was varied between 10.9 and 30.4. Heat transfer coefficients seemed to have reached a steady value within 30 minutes as the case with pure water. But, decrease in heat transfer coefficient continued for over $1{\sim}2$ hours for inclination angle of $0^{\circ}$, and oscillation in heat transfer was observed for certain inclination angles and aspect ratios for over 10 hours. Oscillation shape and period depended on the aspect ratio and inclination angle. For example, the oscillation period for $0^{\circ}$ was more than twice that for $60^{\circ}$. The maximum Nusselt number occurred at the inclination angle of $30^{\circ}$, and the minimum occurred at $60^{\circ}$ for Rayleigh number less than 1.E5. However the present results were obtained with aggregated nanofluid and would be devoid of generalities.

• KIEAE Journal
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• v.14 no.1
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• pp.67-74
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• 2014

There have distinctly been no the installation criteria and maintenance management of BIPV systems, although the BIPV market is consistently going on increasing. In addition, consideration of the BIPV generation quantity which has been installed at several diverse places is currently almost behind within region in Korea. Therefore, the main aim of this study is to evaluate the BIPV generation and to be base data of reducing rate depending on regional installation angles using PVpro which was verified by measured data. Various conditions were an angle of inclination and azimuth under six major cities: Seoul, Daejeon, Daegu, Busan, Gwangju, Jeju-si for the BIPV system generation analysis. As the results, Seoul showed the lowest BIPV generation: 1,054kWh/kWp.year, and Jeju-si have 5percent more generation: 1,108.0kWh/kWp.year than Seoul on horizontal plane. Gwangju and Daejeon turned out to have similar generation of result, and Busan showed the highest generation: 1,193.5kWh/kWp.year, which was increased by over 13percent from Seoul on horizontal plane. Another result, decreasing rate of BIPV generation depending on regional included angle indicate that the best position was located on azimuth: $0^{\circ}$(The south side) following the horizontal position(an angle of inclination: $30^{\circ}$). And the direction on a south vertical position(azimuth: $0^{\circ}$, an angle of inclination: $90^{\circ}$) then turned out reducing rate about 40percent compared with the best one. Therefore, these results would be used to identify the installation angle of the BIPV module as an appropriate position.

• Journal of the Korean Geotechnical Society
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• v.27 no.11
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• pp.27-37
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• 2011

A series of centrifuge model tests to investigate the suction pile pullout loading capacity in sand have been performed. The main parameters that affect the pullout loading capacity of a suction pile include the mooring line inclination angle and the padeye position of the suction pile. With respect to the padeye position, the maximum pullout loading capacity is obtained when the padeye position is near 75% of the pile length from the top. The direction of the pile rotation changes when the padeye position reaches somewhere near 50~75% for all mooring line inclination angles. The translation displacement of suction pile to develop the time of maximum pullout loading capacity decreased as the mooring line inclination angle increased. In addition, the vertical displacements of the center of a suction piles for all cases appeared to develop toward the ground surface.

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.195-200
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• 2020

In this study, the flow analyses were performed on the fluid clutch turbine blade shapes of models 1, 2 and 3, with eight turbine blades tilted at 45 °, 40 °, and 35 ° angles on the propulsion shaft, respectively. The larger the angle of inclination on the propulsion shaft, the higher the flow pressure among the flow models after the back of the turbine blades. On the other hand, the smaller the angle of inclination on the propulsion shaft of the turbine wing, the lower the flow rate. It can be seen that the smaller inclination angle of the turbine blade surface on the propulsion shaft, i.e., the wing shape close to perpendicular to the flow of fluid, is more suitable for efficiently connecting and disconnecting the fluid clutch. By applying the flow analysis by type of turbine blade of fluid clutch,the study result at this paper is considered to be favorable as the convergent research material which can apply the aesthetic design.

• Advances in concrete construction
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• v.13 no.1
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• pp.45-69
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• 2022

This paper investigates the shear behavior of reinforced concrete haunched beams (RCHBs) without stirrups. The research objective is to study the effectiveness of the ideal steel fiber (SF) ratio, which is used to resist shear strength, besides the influence of main steel reinforcement, compressive strength, and inclination angles of the haunched beam. The modeling and analysis were carried out by Finite Element Method (FE) based on a software package, called Atena-GiD 3D. The program of this study comprises two-part. One of them consists of nine results of experimental SF RCHBs which are used to identify the accuracy of FE models. The other part comprises 81 FE models, which are divided into three groups. Each group differed from another group by the area of main steel reinforcement (A_s) which are 226, 339, and 509 mm². The other parameters which are considered in each group in the same quantities to study the effectiveness of them, were steel fiber volumetric ratios (0.0, 0.5, and 1.0)%, compressive strength (20.0, 40.0, 60.0) MPa, and the inclination angle of haunched beam (0.0°, 10.0°, and 15.0°). Moreover, the parametric analysis was carried out on SF RCHBs to clarify the effectiveness of each parameter on the mechanical behavior of SF RCHBs. The results show that the correlation coefficient (R²) between shear load capacities of FE proposed models and shear load capacities of experimental SF RCHBs is 0.9793, while the effective inclination angle of the haunched beam is 10° which contributes to resisting shear strength, besides the ideal ratio of steel fibers is 1% when the compressive strength of SF RCHBs is more than 20 MPa.

• Advances in concrete construction
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• v.14 no.5
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• pp.299-307
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• 2022

Cement-based matrixes have low tensile strength and negligible ductility. Adding fibres to these matrixes will improve their mechanical properties and make these composites suitable for structural applications. Post-cracking tensile strength of steel fibers-reinforced cementitious composite materials is directly related to the number of transverse fibers passing through the crack width and the pulling-out behavior of each of the fibers. Therefore, the exact recognition of the pullout behavior of single fibers is necessary to understand the uniaxial tensile and bending behavior of steel fiber-reinforced concrete. In this paper, an experimental study has been carried out on the pullout behavior of 3D (steel fibers with totally two hooks at both ends), 4D (steel fibers with a total of four hooks at both ends), and 5D (steel fibers with totally six hooks at both ends) in which the fibers have been located either perpendicular to the crack width or in an inclined manner. The pullout behavior of the mentioned steel fibers at an inclination angle of 0, 15, 30, 45, and 60 degrees and with embedded lengths of 10, 15, 20, 25, and 30 millimetres is studied in order to explore the simultaneous effect of the inclination angle of the fibers relative to the alongside loading and the embedded length of fibers on the pullout response in each case, including the maximal pullout force, the slip of the maximum point of pullout force, pullout energy, fiber rupture, and concrete matrix spalling. The results showed that the maximum pullout energy in 3D, 4D, and 5D steel fibers with different embedded lengths occurs at 0 to 30° inclination angles. In 5D fibers, maximum pullout energy occurs at a 30° angle with a 25 mm embedded length.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.8
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• pp.1131-1139
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• 2001

Experimental results are presented, which describe the effect of blowing ratio on film cooling from two rows of holes with opposite orientation angles. The inclination angle is fixed at 35°, and the orientation angles are set to be 45°for the downstream row, and -45°for the upstream row. The studied blowing ratios are 0.5, 1.0 and 2.0. The boundary layer temperature distributions are measured using thermocouple at two downstream locations. Detailed adiabatic film cooling effectiveness and heat transfer coefficient distributions are measured with TLC(Thermochromic Liquid Crystal). The adiabatic film cooling effectiveness and heat transfer coefficient distributions are discussed in connection with the injectant behaviors inferred from the boundary layer temperature distributions. Film cooling performance, represented by heat flux is evaluated from the adiabatic film cooling effectiveness and heat transfer coefficient data. The results show that the investigated geometry provides improved film cooling performance at the high blowing ratios of 1.0 and 2.0.