• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.105-110
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• 2008

The cross-section data are generally used for hydraulic and hydrologic modeling. However, when the detailed data of river channel are required, it is not available to use because of too wide distance of the offset between cross-sections. Also, the actual form of river channel cannot be reflected with the general interpolation methods which is considering straight line between acquired points. The aim of this paper is to present an algorithm which is to interpolate point using bilinear method and to estimate random cross-section between two surveyed cross-section data. And it is supposed that the proposed algorithm can be able to offer available data for hydraulic and hydrologic modeling.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.5
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• pp.1191-1197
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• 1994

The purpose of this study is to examine morphometric characteristics in a channel bend reach. The new shape factor is suggested that channel deformation rate of cross section (${\Delta}A_s$) showed the variation of concentrated location of force due to the current and the variation of erosional section in alluvial channel. In the downstream direction the meaning of decreasing "${\Delta}A_s$" is the stability of channel bed. This study was analyzed morphological characteristics of cross section-width of channel ($W_s$), width to the thalweg ($W_{th}$), maximum depth ($D_{th}$)-on the Guem River, and typical cross sections in channel bend were proposed. The channel migration rate (M) for the study river was represented that the zones of curvature ratio (R/W) with 2~4 were larger 12% than other zones.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.4 s.23
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• pp.57-65
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• 2006

In this study, hydraulic model same as natural channel with junction area and curved reach is constructed, and after that the variation of difference of the water surface elevation at cross section in junction area is analyzed using constructed hydraulic model. In junction area, the variation of maximum water level based on downstream section is more affected in discharge ratio at upstream than downstream. The maximum water level increased as closed to junction and the peak level appeared at just downstream of junction. The slope of water elevation at cross section is affected in section shape and decreased as discharge ratio is reduce. The expressed formulas developed in the channel consist of constant curvature and section shape showed difference of 60% with measured value, but the suggested formula in this study to compute difference of water surface elevation showed difference of 10% with measured value.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.484-490
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• 2017

In order to examine flow characteristics according to the shape of the meandering low flow channel in the compound cross section typed straight channel, we assumed the representative channel type in Korea and confirmed the validity of the 3D numerical simulation by carrying out the hydraulic model. Based on this study, numerical simulations were also conducted on other types of river channel. As a result of the numerical model test (using the velocity value measured by the water depth observation from the hydraulic model test), it was confirmed that the numerical simulation results are in good agreement with the numerical simulation results. As a result of analyzing the flow field according to the changes in the shape of the low flow channel, it was confirmed that the secondary flow examined in the previous studies occurred. Also, it was confirmed that the maximum flow velocity point moves according to the expansion cross sectional area of flow in high flow plain. Ultimately, it is thought that it is necessary to understand the position of the water impingement (which is an important factor in river design) and the extent of the impact because the change of the channel width affects the flow.

• Journal of Power System Engineering
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• v.17 no.1
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• pp.64-70
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• 2013

The heat transfer and friction factor characteristics of turbulent flows in three stationary channels have been investigated experimentally to check out the effect of divergence ratio. These are a constant cross-sectional channel and two diverging channels with ratio of divergence(Dho/Dhi) of 1.16 and 1.49. The measurement was conducted within the range of Reynolds numbers from 15,000 to 89,000 and the dimension of uniform cross-sectional test section is $100mm{\times}100mm$ at the cross section and 1,000 mm in length. The measurements of heat transfer coefficients and friction factors in the uniform channels were conducted as a reference. Because of the streamwise flow deceleration, the heat transfer and friction factor characteristics in the diverging channel were quite different from those of the constant cross-sectional channel. The effective friction factors and convective heat transfer coefficients increased with increasing the ratio of divergence of the channel.

• Journal of Korea Water Resources Association
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• v.37 no.7
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• pp.527-540
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• 2004

In order to investigate characteristics of the primary flow and the secondary currents in the meandering channel, laboratory experiments were conducted in the meandering channel made up of alterative bends haying 120。 arc angle. Experiments were performed in two types of cross-sections, a rectangular cross-section and a curved cross-section which was made to adopt a beta probability function. Three-dimensional velocity fields were measured using a micro-ADV. As the result of experiments, in case of the rectangular cross-section, the primary flow occurred taking the shortest course, which is similar to the result of previous researches. In case of the curved cross-section, the primary flow was expected to occur along the thalweg. but it occurred almost along the shortest way. This is considered due to effects of bottom roughness and sinuosity Not only a main cell but also a secondary cell of secondary currents were clearly shown by mean of the stream function. The secondary current intensity has the maximum value near the apex of the second bend for cases of both rectangular and curved cross-sections. However, the value of the secondary current intensity for the curved section is slightly larger than that for the rectangular cross-section. Also, in case of the rectangular cross-section, the higher the ratio of width to depth is, the larger the secondary current intensity is.

• International Journal of Aeronautical and Space Sciences
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• v.10 no.2
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• pp.77-85
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• 2009

A two-dimensional cross-section analysis program based on the finite element method has been developed for composite blades with arbitrary cross-section profiles and material distributions. The modulus weighted approach is used to take into account the non-homogeneous material characteristics of advanced blades. The CLPT (Classical Lamination Plate Theory) is applied to obtain the effective moduli of the composite laminate. The location of shear center for any given cross-sections are determined according to the Trefftz' definition while the torsion constants are obtained using the St. Venant torsion theory. A series of benchmark examples for beams with various cross-sections are illustrated to show the accuracy of the developed cross-section analysis program. The cross section cases include thin-walled C-channel, I-beam, single-cell box, NACA0012 airfoil, and KARI small-scale blades. Overall, a reasonable correlation is obtained in comparison with experiments or finite element analysis results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.143-150
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• 1994

When the transverse bed slope ($S_t$) in channel bend is more than 0.1, it may produce undesirable results on the bed topography of the cross section. The linear relationship for $S_t$ results in zero or negative flow depths at the shallow $S_t$de of the cross section (i.e., inner bank). The exponential relationship for $S_t$ results in excessive flow depths at the deep side of the cross section (i.e., outer bank). This problem can be solved by combining the best features of both relationships described above. From the study, the linear relationship can be applied for the deep $S_t$de of the cross section. But the exponential relationship is suitable for the shallow side. Therefore, the new relationship of $S_t$ is clarified mathematically. A new mathematical model for bed topography is developed herein which takes accounts of the phase lag and the influence of the width to depth ratio. This model is used to analyze two sets of data: one from laboratory channel and the other from natural channel. A good agreement is found between the observed and the calculated bed topography based on the analysis of two sets of data.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.5
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• pp.3-9
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• 2007

In this study, the effect of the purification materials is analyzed and tested by Flow 3D and Hydraulic model test. Three dimension numerical analysis led from the research that sees abnormal form and the size back of the water purification material conferred the flowing water conduct inside the test channel against the test condition. Comparison it analyzed the flux distribution, a water depth of the channel which establishes the water purification materials the cross section, an interval of the water purification material, a conference with general channel, it change executed. As a result, the cross section ratio of the purification materials against and a flux change from the test which it sees. The interval of the purification materials in order to prevent three dimension that follows in decrease of increase and flux must decide an interval.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.78-83
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• 2004

The channel-type lining board that partial welded on many partition frames is used to normal servicing lining board type. On this study is to investigate existing channel-type lining board's capacity by using the static loading test. From this study, to develop new-type lining board which reflect well cross section area and sectional modulus of existing channel-type lining board. Six types FEM model are adopted. The accumulated test results of stress conditions and deflections by section shapes will be used to analyzed the relation between the capacity and the section shape. With the comparing the results of static loading test and FEM analysis.