• Title/Summary/Keyword: Experiment of scale model

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Construction of a Hydraulic Scale Model for Representing the Field Tracer Experiment in River (하천 현장 실험 재현을 위한 수리모형 장치 제작)

  • Chun, Il Young;Kim, Ki Chul;Lee, Jung Lyul;Suh, Kyung Suk
    • Journal of Radiation Industry
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    • v.2 no.3
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    • pp.155-161
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    • 2008
  • A hydraulic scale model was constructed to investigate the characteristics of flows and pollutant transport in laboratory. The distorted hydraulic scale model by assuming Froude similarity was adopted to represent hydrodynamics and dispersion in a river system. The scale model was composed of water reservoir, slope control part, booster pump, distributing plate and main channel. A constructed scale model will be used to present the overall concentration profiles of tracer and a research will be performed to convert the measured values using a hydraulic scale model to real field scale.

A Study on the Development of Scientific Experimental Model for the Home Economics Textiles Class in High School (고등학교 가정과 피복재료 탐구실험학습 모형 개발)

  • 라상숙;이전숙;김용숙
    • Journal of Korean Home Economics Education Association
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    • v.10 no.1
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    • pp.153-169
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    • 1998
  • The purposes or this study were to develop the scientific experimental model, experimental guidelines for teachers, experiment planning & report form for students, and evaluation scales for the Home Economics Textiles class in high school. First, through review of literature concerned, scientific experimental model was defined, and the usefulness of this model on the teaching situation testified on other subjects such as Physics and Bilolgy, was reviewed. Secondly, scientific experimental model, experimental guidelines for teachers, experiment planning & report form for students, and evaluation scale were developer on the bases on APU evaluation model, experimental guidelines for teachers, experiment planning & report form for students, evaluation scale applicable to the teaching situation ere established by analysing the significant differences scientifically.

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Validity Evaluation of Scale Model Experiments in Architectural Daylighting Performance (자연채광 성능평가에 있어서 축소모형실험 방법론의 유용성 검증에 관한 연구)

  • Kim, J.T.;Chung, Y.G.;Jeong, I.Y.;Hwang, M.K.
    • Journal of the Korean Solar Energy Society
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    • v.22 no.2
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    • pp.61-69
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    • 2002
  • Daylighting is a powerful vehicle of architectural expression and provides buildings a living quality due to constantly changing properties in intensity and color. As an environmental system, daylighting should be subjected to the same level of rigorous analysis and review that any environmental system receives. For example, increasing cooling loads and causing visual displeasure are easily occurred owing to the excessive sunlight through windows. Therefore, daylighting performance attributes and physical characteristics must be described qualitatively and quantitatively in early design process. In various architectural daylighting performance evaluation methods, the scale model experiment can be applied due to it's simplicity and usefulness. So, this study aims to evaluate the validation of scale model experiments in architectural daylighting performance. For the purpose, two scale model experiments under clear sky are conducted. And, the validation of the experiments are evaluated by computer simulations.

Investigation of cause and magnitude of scale effect occurring in model experiments of fishing nets (그물어구의 모형 실험시에 발생하는 축척비 영향의 원인 및 크기 조사)

  • Kim, Dae-An
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.1
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    • pp.1-9
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    • 2011
  • In order to investigate the cause and magnitude of scale effect occurring in the model experiments of fishing nets, five pairs of Nylon pyramid nets and one pair of PE ones in which all the two nets paired were equal each other in the factors determining their flow resistance, i. e., the ratio d/l of diameter d to length l of bars, the angle f between two adjacent bars, the attack angle q of nettings to the water flow, and the wall area S of nets, and different in the values of d and l were prepared. Then, the nets were attached to the circular steel frame alternately and their flow resistances with shapes in water were measured on the sea ascribing no turbulent flows by using the tension meter made of a block bearing for the experiment. All the Nylon nets were spreads out easily in water to form a circular cone at relatively low velocity of water and showed the resistance smaller a little in the nets with larger d and l than them with smaller d and l, because the filtration of water through meshes become easier in nets especially with larger l. But PE nettings were not spread out sufficiently on account of their small flexibility and showed higher resistance especially in them with thicker twines. Therefore, the difference in bar length or mesh size and flexibility of nettings between prototype and model nets are regarded to become factors ascribing scale effect. Especially the influence of the difference in mesh size may become large significantly in actual model experiments because the mesh size of model nets is decided at much larger value than that given by scale ratio and so the difference of mesh size between the two nets become much larger than that between nets used in this experiment.

A Study on the Assimilation of High-Resolution Microwave Humidity Sounder Data for Convective Scale Model at KMA (국지예보모델에서 고해상도 마이크로파 위성자료(MHS) 동화에 관한 연구)

  • Kim, Hyeyoung;Lee, Eunhee;Lee, Seung-Woo;Lee, Yong Hee
    • Atmosphere
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    • v.28 no.2
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    • pp.163-174
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    • 2018
  • In order to assimilate MHS satellite data into the convective scale model at KMA, ATOVS data are reprocessed to utilize the original high-resolution data. And then to improve the preprocessing experiments for cloud detection were performed and optimized to convective-scale model. The experiment which is land scattering index technique added to Observational Processing System to remove contaminated data showed the best result. The analysis fields with assimilation of MHS are verified against with ECMWF analysis fields and fit to other observations including Sonde, which shows improved results on relative humidity fields at sensitive level (850-300 hPa). As the relative humidity of upper troposphere increases, the bias and RMSE of geopotential height are decreased. This improved initial field has a very positive effect on the forecast performance of the model. According to improvement of model field, the Equitable Threat Score (ETS) of precipitation prediction of $1{\sim}20mm\;hr^{-1}$ was increased and this impact was maintained for 27 hours during experiment periods.

Model test on the net mouth shape of a gape net according to current speeds in Jindo area, Korea (전남 진도지역 낭장망의 유속에 따른 망구형상 변화에 관한 모형실험)

  • Kim, Seonghun;Lee, Donggil;Lim, Jihyun;Park, Seongwook
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.1
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    • pp.146-153
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    • 2015
  • A model net experiment of the gape net for anchovy in Jindo, Jeollanam-do was carried out to investigate the net shape and hydrodynamic resistance using circulating water channel. The model net was made 1/33 down scale by Tauti's similarity method and the range of experimental current speed was from 0.5 knot to 3.5 knot (increasing 0.5 knot interval). The net mouth height in 0.5 knot of the minimum experiment current speed was shown 26.0 cm (full-scale conversion value 8.58 m). The net mouth height and mouth area in 1.5 knot of the same current speed with a gape net fishing ground were shown 20.0 cm (full-scale conversion value : 6.60 m) and about $507.9cm^2$ (full-scale conversion value : $55.31m^2$). The net mouth height and area were decreased with increase the experimental current speed. The hydrodynamic resistance of the model net in 1.5 knot current speed was shown 1.11 kgf and the value of full-scale conversion by Tauti's method was shown 3.996 ton.

A Study on Manufacturing and Experimental Techniques for the 1/5th Scale Model of Precast Concrete Large Panel Structure (프리캐스트 콘크리트 대형판 구조물의 1/5 축소모델 제작 및 실험기법 연구)

  • 김상규;이한선
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.198-203
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    • 1995
  • The objective of this study is to provide the information on the techniques of manufacturing and experiment in small scale modeling of precast concrete(P.C.)large panel structures. The adopted scale was 1/5th 4types of experiments were performed : material tests for model concrete and model reinforcement, compressive test of horizontal joint, shear test of vertical joint and cyclic static test of 2-story subassemblage structure. Based on the experimental results, the following conclusions are drawn: (1)Model concrete may have in general larger compressive strength than expected. (2) Model reinforcement can show less ductility if the annealing processes were performed without using vaccuum tube. (3) Failure modes of horizontal and vertical joints were almost same for both prototype and model. But the strength of model appears to be higher than required by similitude law. (4)Hysteretic behavior of 1/5 scale subassemblage model can be made quite similar to prototype's if the ductility of model reinforcement and compressive strength of model concrete could be representative of those of prototype.

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Study on the Ejected Plume from Opening Regarding Side-wall Effect in Fire (측벽효과를 고려한 개구부 분출화염 거동 연구)

  • Jeong, Jae-Gun;Shin, Yi-Chul
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.219-220
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    • 2016
  • The behavior of fire plumes has not yet been clearly identified for cases where sidewalls are installed near an opening in an unconfined space. In this research, we aim to quantitatively identify the effects on fire spread when sidewalls are located on both sides of an opening. Specifically, we focus on the effects on the fire plume of the relation between the location of sidewalls and the opening, and carry out a scale-model experiment to devise a flame height model and to evaluate the temperature distribution along the central axis of the flame.

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Real Scale Experiment for Suspended Solid Transport Analysis and Modeling of Particle Dispersion Model (부유 물질 거동 분석을 위한 실규모 실험 및 입자 분산 모형 적용)

  • Shin, Jaehyun;Park, Inhwan;Seong, Hoje;Rhee, Dong Sop
    • Journal of Convergence for Information Technology
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    • v.10 no.12
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    • pp.236-244
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    • 2020
  • In this research a suspended solid transport experiment was conducted in the river experiment center to find the characteristics and dispersion of the material. Modeling by the particle dispersion model was also executed to reproduce the suspended solid transport. The suspended solid was consisted of a mixture of silica and water using a mixing equipment, which was then introduced into a real-scale flume and measured with the laser-diffraction based particle size analyzer(LISST) to find the concentration of the material. The comparison between the measured suspended solid concentration using drone images and particle size analyzers, with the model showed a good match overall, which proved the applicability of the model. Along with finding the model applicability, the research showed the potential for suspended solid estimation in high flow situations with high rainfall.

쌍끌이 중층트롤어업의 연구 ( IV ) ( a Study on the Midwater Pair Trawling ( IV )

  • Jang, Chung-Sik;Lee, Byeong-Gee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.1
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    • pp.7-15
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    • 1996
  • Full scale experiment was carried out in the southern sea of Korea to compare some important factors tested in the model experiment. The results obtained can be summarized as follows ; 1. The changing aspect of mouth performance of the full scale net was almost coincided with the results obtained by the model experiment. The vertical opening(H) and the opening area(S) can be expressed as a function of the towing velocity(V) as H=48.78. $e^0.38V$(unit: m, k't) S= 1,443 .$e^-0.25V$(unit: $m^2V$, k't) 2. The changing aspect of working depth of the full scale net was almost coincided with the results obtained by the model experiment. The depth(D) can be expressed as a function of the towing velocity(V) and the warp length(L) as D=92.49.$V^1.37$(unit: m, k't, L= 150m) D= 12.07+0.32. L (unit: m, V=2k't) [)= - 7.90+0.22 . L (unit: m, V=3k't) 3. Some problems were found to operate A - type full scale net by common bottom pair trawlers. The problems can be summarized as follows; (1) Entangling of wing and square head ropes while net casting.(2) Man power needed and time spent for net hauling by common bottom trawlers increased considerably.( 3) Tearing of nettings caused by over -load of tension and entangling of net pendant while net hauling. To solve these problems, the trawlers are favorable to be equipped with variable pitch propeller and llet drum. While the net is favorable to be constructed with trifurcated net pendant in stead of quadrifurcated net pendant used at present.

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