• Title/Summary/Keyword: erosion

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An Experimental Investigation of Particle Impingement Erosion in Hydraulic Systems (유압시스템의 입자 침해 침식의 실험적 고찰)

  • 이재천;김성훈
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.2
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    • pp.117-122
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    • 2002
  • This study assesses the wear process of particle impingement erosion which is a major source of erosion among fluid power components. First, Bitter's theory was modified to simplify engineering calculations. Second, actual experiments were conducted to validate the modified equation. And the effect of concentration and size distribution of impinging particles was tested. Little deviation from the prediction of the modified equation was observed. To develop complete analytical approach to the erosion mechanism, further experimental data are required to establish a correlation with other engineering parameters.

The ECBL approach for interactive buckling of thin-walled steel members

  • Dubina, Dan
    • Steel and Composite Structures
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    • v.1 no.1
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    • pp.75-96
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    • 2001
  • Actual buckling curves are always characterised by the erosion of ideal buckling curves. In case of compact sections this erosion is due to the imperfections, while for thin-walled members, a supplementary erosion is induced by the phenomenon of coupled instabilities. The ECBL approach- Erosion of Critical Bifurcation Load - represents a practical and convenient tool to characterise the instability behaviour of thin-walled members. The present state-of-art paper describes the theoretical background of this method and the applications to cold-formed steel sections in compression and bending. Special attention is paid to the evaluation methods of erosion coefficient and to their validation. The ECBL approach can be also used to the plastic-elastic interactive buckling of thin-walled members, and the paper provides significant results on this line.

The characteristics of anti-erosion for MgO protecting layer in plasma display panel (플라즈마 디스플레이 보호막으로 사용되는 마그네슘 산화막(MgO)의 내식각 특성)

  • 최훈영;이석현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.2
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    • pp.163-169
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    • 2000
  • In this paper, we showed the erosion characteristic of MgO protector layer releated to lifetime of plasma display panel(PDP). We observed MgO erosion characteristic as a functions of deposition conditions, pressure and distance between electrodes. In RIE condition of Xe gas, the lowest erosion rate appears in the conditions of no heating bias voltage -30V and pressure 5mtorr. In general, as deposition rate increases, erosion rate decreases. In real panel, when the gap distance between electrodes is narrow and the pressure is low, the heavy plasma damage appears. Also, the surfaces between electrodes and on the bus electrode are extremely damaged.

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An Experimental Investigation of Particle Impingement Erosion in Hydraulic System (유압시스템의 입자 침해 침식의 실험적 고찰)

  • 이재천
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.15-21
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    • 2001
  • This study assesses the wear process of particle impingement erosion which is a major source of erosion among fluid power components. First, Bitter's theory was modified to simplify engineering calculations. Second, actual experiments were conducted to validate the modified equation. And the effect of concentration and size distribution of impinging particles was tested. Little deviation from the prediction of the modified equation was observed. To develop an analytical approach to the erosion mechanism, further experimental data are required to establish a correlation with other engineering parameters.

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Influences of Gas and Solid Particle on the Cavitation Erosion-Corrosion (케비테이션 침식-부식에 미치는 기체와 고체입자의 영향)

  • Lim, Uh-Joh;Beak, Suk-Jong;Hwang, Jae-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.29 no.2
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    • pp.124-131
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    • 1993
  • Recently. with the rapid development in large sea water systems. there occurs much interest in the study of erosion-corrosion. In this study. the mild steel(SB41) was tested by using of a erosion-corrosion test apparatus with fountain-jet and was investigated under the environments of liquid, air-liquid 2 phase flow and solid particle-liquid 2 phase flow. Main results obtained are as follows : 1. The weight loss by corrosion-erosion in air-liquid 2 phase flow are more increased than that in only liquid solution. 2. Effect of air-liquid 2 phase flow on corrosion-erosion sensitivity becomes more sensitive in natural seawater than that in distilled water. 3. The corrosion potential by corrosion-erosion in air-liquid and solid particle-liquid 2 phase flow becomes noble than that of only liquid solution.

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Effect of Vanadium Addition on the Cavitation Erosion Resistance of Fe-Cr-Ni-Si-C Hardfacing Alloy (Fe-Cr-Ni-Si-C계 경면처리 합금의 Cavitaon Erosion 저항성에 미치는 Vanadium 첨가의 영향)

  • 김경오;김준기;장세기;김선진;강성군
    • Journal of the Korean institute of surface engineering
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    • v.31 no.5
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    • pp.297-303
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    • 1998
  • The influences of vanadium addition on the cavitation erosion resistance pf Fe-Cr-Ni-Si-C hardfacing alloy were investigated using a vibratory apparatus up to 30 hrs. It was shown that 1wt.%V additioned alloy improved the resistance to cavitation damage. However, further increase in V content up to 2wt.% reduced the cavitation erosion resistance. It was considered that the addition of V developed the cavitation erosion resistance by reducing the stacking fault energy of Fe-Cr-Ni-Si-C alloy. However, the further increase in V content seemed to reduce the cavitation erosion resistance by increasing the matrix/carbide interfacial area, which was the preferential sites of the cavitation damage.

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An Approximate Solution for Diffraction-Induced Shoreline in a Double Headland and Comparison with Field Measurement

  • Shoaib, Muhammad;Kim, Dong Hee;Lee, Jung Lyul
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.193-193
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    • 2016
  • In past decades beach erosion has been remarkably severe along coasts of different parts of the world, so that distinct types of coastal protective measures have been implemented; seawalls, wave-dissipating breakwaters, groins, artificial headlands or detached breakwaters have been constructed. In recent years, at Bongpeong beach, South Korea, an artificial headland was constructed to stop the beach erosion. The structure resulted in severe beach erosion of the adjoining places. In order to stop the consequences, another headland was constructed at some distance, but the construction of double headland did not prevent the erosion significantly. This paper focuses on the accurate design of the artificial double headland construction. The study presents the application of equilibrium shoreline empirical formula of parabolic type to estimate the equilibrium stages of the artificial double headland beaches and an analytic solution is presented in the present study. The research has solved the empirical formula of parabolic type to find the optimum result by considering the essential parameters that influence the erosion after the construction of double headland.

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The Theoretical Analyses of the Soil Erosion and Conservation 2. The Theoretical Expresion of Erosion Tolerance for the Soil Conservation (토양의 침식과 보존에 관한 이론적 분석 2. 토양침식의 내성에 관한 이론)

  • 장남기
    • Asian Journal of Turfgrass Science
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    • v.10 no.1
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    • pp.31-40
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    • 1996
  • The mechanical expresion provides for the use of Soil property reserves and permanent protec-tion or improvement of soil resources in accordance with measurable standards. If the functions I (initial soil property), E (soil erosion), R (soil renewal), and M. (minimum allowable value) are assumed to be integrable in region A, erosion tolerance over a region is leaded to ${\int}_A{\int}I(m, cl, re, ch, b)dA-{\int}_A{\int}{\{\int}_{to}^{\infty}[E(w, re, c, re, ch, b, t)-R(m, ch, re, b, t)]dt}\dA{\geqq}{\int}_A{\int}M_i(m, cl, re, ch, b)dA$ were variable factors are m=parent material of soil, cl=climate, re=relief or topography, ch=soil characteristics, r=rain or water, w=wind, b=biota, and t=time.

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Parcel based Information System for Sediment Disaster by using Mobile GIS (모바일 GIS를 이용한 필지별 토사재해정보시스템 개발)

  • Lee, Geun-Sang;Choi, Yun-Woong
    • Journal of Cadastre & Land InformatiX
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    • v.46 no.1
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    • pp.59-74
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    • 2016
  • The collapses of retaining walls or embankments, the soil erosion and landslides around urban areas are occurring by heavy rainfalls because of the recent climate change. This study conducts the soil erosion modeling, while applying the spatial information such as soil maps, DEM and landcover maps to the RUSLE model. Especially this study draws up the soil erosion grade map and the unit soil erosion grade map by parcels through coupling the soil erosion with the cadastral map, and by that can calculate the number of parcels by soil erosion grades. Also the sediment disaster information system based on the mobile GIS is developed to identify the soil erosion grades of site in the urban plannings and the construction fields. The sediment disaster information system can identify the present conditions of the registers of lands, buildings and roads, and confirm the RUSLE factors, the soil erosion, the sediment disaster grades by parcels. Also it is anticipated that this system can support the sediment disaster work of site effectively through searching the locations and attributes of the specific parcels by Administrative Dong and the soil erosion grades.

Creation of Natural Terrain by Erosion Simulation (자연스러운 지형 생성을 위한 침식 시뮬레이션)

  • Han, Yeong-Deok
    • Journal of Korea Game Society
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    • v.15 no.6
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    • pp.171-182
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    • 2015
  • Existing hydraulic terrain erosion simulations mainly focus on small scale terrain deformations. In this paper, we propose a simulation method combining hydraulic terrain erosion and thermal erosion, by which a natural large scale terrain of mountainous regions with river networks can be created. For water movement we use the pipe model of shallow water simulation, and for the easy formation of watercourse we use velocity dependent erosion, also we apply thermal erosion for the formation of V-form slopes in the vicinity of stream lines. As a result, we can obtain good natural shaped terrains for certain ranges of $K_c$(sediment capacity constant) and $K_v$(velocity dependent erosion strength) values. Also we present improved thermal erosion method, and suggest a way to avoid problems caused by large $K_c$value.