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Experimental studies on the erosion rate of different heat treated carbon steel economiser tubes of power boilers by fly ash particles

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International Journal of Minerals,Metallurgy and Materials 2009年第5期16卷 534-539页

作者： T.A.Daniel Sagayaraj S.Suresh M.Chandrasekar Department of Mechanical Engineering National Institute of Technology Tiruchirappalli-620015Tamil NaduIndia

The experimental investigations on the effect of the fly ash particle size, velocity, impingement angle, and feed rate were done with an emphasis on the effect of erosion on annealed SA 210 GrA1 （A） and normalized SA 210 GrA1 （N） carbon steel economizer-tube materials. erosion rates were evaluated with different impingement angles ranging from 15° to 90°, at four different velocities of 32.5, 35, 37.5, and 40 m/s, and at four different feed rates of fly ash particles of 2, 4, 6 and 8 g/min. The erodent used was fly ash particles, sizes ranging from 50-250 μm of irregular shapes. erosion rate is found to be the maximum at the impingement angle of 30°. erosion rates of the carbon steel tube in different heat treatment conditions, annealed and normalized, at a constant velocity of 32.5 m/s with different angles were studied. In all cases of feed rates, impingement angles, particle sizes, and velocities of fly ash particles, it has been found that the erosion rate of the annealed tube is less than that of the normalized tube. Empirical correlations for erosion rate relating the velocity, size, feed rate, and impingement angle of the particles and elongation property of the target materials were arrived. Morphologies of the eroded surface were examined by scanning electron microscope （SEM）.

关键词： erosion rate economiser tubes annealing normalizing

The effects of plant density of Melastoma malabathricum on the erosion rate of slope soil at different slope orientations

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International Journal of Sediment Research 2015年第2期30卷 131-141页

作者： Aimee Halim Osman Normaniza Institute of Biological Sciences Faculty of ScienceUniversity of Malaya

Malaysia's cut slopes,especially for road lines accommodation,are prone to erosions and *** problems mainly occur due to lack of vegetation cover and strong erosive *** addition,the topography factors have also become a major factor affecting soil ***,this study is aimed at determining the effects of planting density of a selected species,namely Melastoma malabathricum;one,two,and three seedlings per box,on the erosion rate at selected slopes of different orientation(morning and evening sun) at the Guthrie Corridor Expressway,*** six months of observation,treatment with three seedlings/box on the morning sun slope showed a lower erosion rate by 69.2%than those with the same treatment on the evening sun *** addition,the treatment of the three seedlings recorded at month six(final observation) had the highest reduction of soil saturation level(STL),by 23.6%.Furthermore,the physiological values of the species studied,grown on the morning sun slope,were higher in terms of stomatal conductance and photosynthetic rate by 12.1%and 15.8%(three seedlings/box),*** overall results showed that plant density was inversely related to the STL and erosion rate on the *** conclusion,a planting density of three seedlings/box and morning sun orientation gave positive effects on the plant's physiological performance of the slope,reducing the STL,as well as alleviating the erosion rate of slope soils.

关键词： Melastoma malabathricum erosion rate Plant density Physiology Slope orientations Soil saturation level

Transport rate of Surface erosion by the Hydrodynamics

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四川大学学报（工程科学版） 2005年第S1期37卷 81-85页

作者： Yang, Jurui Cao, Shuyou Liu, Xingnian Fang, Duo Dept. of Water Resources and Hydropower Kunming Univ. of Sci. and Tech. Kunming 650051 China State Key Lab. of Hydraulics and Mountain River Eng. Sichuan Univ. Chengdu 610065 China

The coherence and exposure degree are used in analyzing initiation of slope *** initial ve- locity is built by using a critical roiling model.A transport rate formula of slope erosion is established using the Meyer-Peter *** formula is tested by experiment and agrees well but the errors are big when the flow discharge and rain intensity are smaller.

关键词： binding power exposure degree erosion rate thin flow

Contrasted Impact of Land Abandonment on Soil erosion in Mediterranean Agriculture Fields

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Pedosphere 2018年第4期28卷 617-631页

作者： Jesus RODRIGO-COMINO Carlos MARTINEZ-HERNANDEZ Thomas ISERLOH Artemi CERDA Instituto de Geomorfología y Suelos Department of Geography University of Málaga Mdlaga 29071 (Spain) Department of Physical Geography Trier University Trier 54286 (Germany) Department of Geography University of Murcia Murcia 30001 (Spain) Soil erosion and Degradation Research Group Department of Geography University of Valencia Valencia 46010 (Spain)

Abandonment of agricultural land results in on- and off-site consequences for the ecosystem. In this study, 105 rainfall simulations were carried out in agriculture lands of the Mediterranean belt in Spain （vineyards in Malaga, almond orchards in Murcia, and orange and olive orchards in Valencia） and in paired abandoned lands to assess the impact of land abandonment on soil and water losses. After abandonment, soil detachment decreased drastically in the olive and orange orchards, while vineyards did not show any difference and almond orchards registered higher erosion rates after the abandonment. Terraced orchards of oranges and olives recovered a dense vegetation cover after the abandonment, while the sloping terrain of almond orchards and vineyards enhanced the development of crusts and rills and a negligible vegetation cover resulted in high erosion rates. The contrasted responses to land abandonment in Mediterranean agricultural lands suggest that land abandonment should be programmed and managed with soil erosion control strategies for some years to avoid land degradation.

关键词： erosion rate Mediterranean crop rainfall simulation terrace vegetation cover

Influence of Metal Oxides on the Arc erosion Behaviour of Silver Metal Oxides Electrical Contact Materials

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Journal of Materials Science & Technology 2004年第1期20卷 49-52页

作者： P.Verma O.P.Pandey A.Verma School of Physics and Material Science Thapar Institute of Engineering and Technology Patiala-147004 IndiaSchool of Physics and Material Science Thapar Institute of Engineering and Technology Patiala-147004 IndiaMaterials Science and Technology Division Thapar Centre for Industrial Research and Development Patiala-147004 India

In the present work investigations have been made to see the role of metal oxides on the performance of the silver metal oxides electrical contact materials. Silver metal oxide materials of three different compositions Ag-10CdO, Ag-7.6SnO2-2.3ln2O3 and Ag-10ZnO were prepared by internal oxidation process under identical processing conditions. These materials were tested for electrical conductivity, hardness, and erosion loss. Performing an accelerated test on the actual contactor assessed the electrical performance, involving erosion loss and temperature rise of the processed materials. The arc-eroded surface was characterized under scanning electron microscope. The study of the eroded surfaces of contacts indicates that the thermal stability of metal oxides depends on nature of silver-metal oxide interface and their mode of erosion. An attempt is made to correlate the surface features of the eroded contacts with the thermal stability of metal oxides.

关键词： Contact material Microstructure erosion rate

Dating of faults and estimation of surface uplift and erosion rates in the northern margin of Dabie Mountains,China

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Dating of faults and estimation of surface uplift and erosio...

Controls on the regional distribution of landslide dams and implications for fluvial landform evolution in Bhutan and its surrounding area

中国科学院地质与地球物理研究所2012年度（第12届）学术年会

作者： X.B.Tu F.C.Dai Y.S.Pan Institute of Geology and Geophysics Chinese Academy of Sciences

Absolute timing of fault movement provides information about tectonic deformation *** K-Ar dating method has been applied to determine the absolute timing of fault *** key to K-Ar dating of fault gouge is to verify that the illite is of authigenic *** we show effective and convincing evidences for authigenic illite in fault *** characteristics of the authigenic illite reveal that the host rocks were under near-surface environment during fault *** result indicates fault movement in Late Cretaceous in the northern margin of Dabie Mountains orogenic *** to the absolute timing,the uplift and erosion rates of the northern margin of Dabie Mountains are also estimated.

关键词： K-Ar isotopic dating Fault Illite Uplift rate erosion rate

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山地科学学报(英文) 2023年第8期20卷 2107-2132页

作者： ZHANG Qi-yuan HU Kai-heng LIU Shuang LIU Wei-ming Institute of Mountain Hazards and Environment Chinese Academy of Sciences(CAS)Chengdu 610041China University of Chinese Academy of Sciences Beijing 100149China China-Pakistan Joint Research Center on Earth Sciences Islamabad 30001Pakist

The regional distribution of landslide dams can provide valuable insights into the interactions among various factors,including lithology,topography,climate,and fluvial landforms in tectonically active *** rivers are frequently impacted by large-scale landslide damming,which profoundly influence fluvial *** this study,we identified 1652 landslide dams in four major rivers of Bhutan and its surrounding area by remote sensing ***,approximately 71%of these landslide dams are found in regions composed of quartzite or ***-related tectonic activity plays a significant role in governing the distribution of these landslide dams,as approximately 83%of the mapped landslide dams are found within a 10 km radius of the nearest *** majority of the identified landslide dams are situated in areas with relatively modest local relief,ranging from 227 m to 327 *** dams tend to cluster in the tributaries,and the stream power of almost 95%of them is typically below 1×10^(6) kg m^(2) s^(-3).Our data,combining the erosion rate and kernel density map of the landslide dams,reveals that regions with high erosion rates do not consistently align with the major high-density distribution of landslide *** is shown that the distribution of landslide dams is strongly influenced by the valley *** comparison to U-shaped valleys,V-shaped valleys exhibit a higher density of landslide ***,we also find a positive correlation between the landslide-dam distribution density and the erosion rate only in relatively arid regions with mean annual rainfall less than 500 ***,the length of the upstream reach protected by the knickpoint associated with both lithology and landslide damming is about three times longer than that protected by the knickpoint associated only with landslide damming.

关键词： Bhutan Himalayas Landslide dams erosion rate Geomorphological impacts Landscape evolution

Numerical simulation of predicting and reducing solid particle erosion of solid-liquid two-phase flow in a choke

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Petroleum Science 2009年第1期6卷 91-97页

作者： Li Guomei Wang Yueshe He Renyang Cao Xuewen Lin Changzhi Meng Tao State Key Laboratory of Multiphase Flow in Power Engineering Xi＇an Jiaotong University Xi＇an Shaanxi 710049 China China Special Equipment Inspection and Research Institute Beijing 100013 China School of Transport ＆ Storage and Civil Engineering China University of Petroleum Qingdao Shandong 266555 China Petroleum Exploration and Production Research Institute Sinopec Beijing 100083 China

Chokes are one of the most important components of downhole flow-control equipment. The particle erosion mathematical model, which considers particle-particle interaction, was established and used to simulate solid particle movement as well as particle erosion characteristics of the solid-liquid two-phase flow in a choke. The corresponding erosion reduction approach by setting ribs on the inner wall of the choke was advanced. This mathematical model includes three parts： the flow field simulation of the continuous carrier fluid by an Eulerian approach, the particle interaction simulation using the discrete particle hard sphere model by a Lagrangian approach and calculation of erosion rate using semiempirical correlations. The results show that particles accumulated in a narrow region from inlet to outlet of the choke and the dominating factor affecting particle motion is the fluid drag force. As a result, the optimization of rib geometrical parameters indicates that good anti-erosion performance can be achieved by four ribs, each of them with a height （H） of 3 mm and a width （B） of 5 mm equaling the interval between ribs （L）.

关键词： Solid-liquid two-phase flow discrete particle hard sphere model choke erosion rate antierosion numerical simulation

Two-flow model for piping erosion based on liquid-solid coupling

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Journal of Central South University 2013年第8期20卷 2299-2306页

作者： LIANG Yue WANG Jun-jie LIU Ming-wei National Engineering Research Center for Inland Waterway Regulation (Chongqing Jiaotong University) Chongqing 400074 China Key Laboratory of Hydraulic & Waterway Engineering of the Ministry of Education (Chongqing Jiaotong University) Chongqing 400074 China

Previous studies have indicated that piping erosion greatly threatens the safe operation of various hydraulic structures. However, few mathematical models are available to perfectly describe the erosion process due to the complexity of piping. The focus of the present work is to propose a new fluid solid coupling model to eliminate the shortcomings of existing work. A 'pseudo-liquid' assumption is suggested to simulate the particle movement in the erosion process. Then, based on the mass and momentum conservations of the moving particles and flowing water, a new two-flow model is established by using the continuity equations and motion equations. In the model, the erosion rate of soil is determined with a particle erosion law derived from tests results of STERPI. And ERGUN's empirical equation is used to determine the interaction forces between the liquid and the solid. A numerical approach is proposed to solve the model with the finite volume method and SIMPLE algorithm. The new model is validated with the tests results of STERPI. And the soil erosion principles in piping are also explored.

关键词： piping erosion two-flow model liquid-solid interaction erosion rate drag force