共查询到19条相似文献，搜索用时 62 毫秒
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ＥＦＦＥＣＴＯＦＥＸＩＳＴＥＮＣＥＯＦＳＥＤＩＭＥＮＴＰＡＲＴＩＣＬＥＳＯＮＴＨＥＥＮＥＲＧＹＬＯＳＳＯＦＦＬＯＷ￥ＬＩＵＱｉｎｇｑｕａｎ；ＣＨＥＮＬｉａｎｄＬＩＵＤａｙｏｕ（Ａｓｓｏｃ．ＲｅｓｅａｒｃｈＦｅｌｌｏｗ，ＩｎｓｔｉｔｕｔｅｏｆＭｅｃｈａ... 相似文献
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ＴＨＥＦＬＵＣＴＵＡＴＩＮＧＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＨＹＤＲＯＤＹＮＡＭＩＣＦＯＲＣＥＳＯＮＢＥＤＰＡＲＴＩＣＬＥ￥ＷＡＮＧＸｉｎｇｋｕｉａｎｄＡＮＦｅｎｇｌｉｎｇ（ＴｈｅＦｉｎａｎｃｅｗａｓＳｕｐｐｏｒｔｅｄｂｙＮａｔｉｏｎａｌＳｃｉｅｎ... 相似文献
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WU Changwen WANG Lixian 《国际泥沙研究》1995,(1)
ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＶＥＲＬＡＮＤＦＬＯＷＡＮＤＭＥＣＨＡＮＩＳＭＯＦＳＯＩＬＣＯＮＳＥＲＶＡＴＩＯＮＦＯＲＦＯＲＥＳＴＥＤＳＴＥＥＰＨＩＬＬＳＬＯＰＥ（１）ＡｎａｌｙｔｉｃａｌＳｏｌｕｔｉｏｎｔｏｔｈｅＯｖｅｒｌａｎｄＦｌｏｗｏ... 相似文献
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ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＶＥＲＬＡＮＤＦＬＯＷＡＮＤＭＥＣＨＡＮＩＳＭＯＦＳＯＩＬＣＯＮＳＥＲＶＡＴＩＯＮＦＯＲＦＯＲＥＳＴＥＤＳＴＥＥＰＨＩＬＬＳＬＯＰＥ－－（ＩＩ）ＭｅｃｈａｎｉｓｍｏｆＳｏｉｌＣｏｎｓｅｒｖａｔｉｏｎＯｖｅｒＳｔ... 相似文献
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ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＦＯＲＳＥＤＩＭＥＮＴＴＲＡＮＳＰＯＲＴＣＡＰＡＣＩＴＹＯＦＨＹＰＥＲＣＯＮＣＥＮＴＲＡＴＥＤＦＬＯＷＩＮＤＩＶＥＲＳＩＯＮＣＡＮＡＬＳ￥ＣＡＯＲｕｘｕａｎ；ＷＵＰｅｉａｎ；ＲＥＮＸｉａｏｆｅｎｇａｎｄＬＩＵＭｉｎｇ... 相似文献
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ＣＯＭＰＡＲＩＳＯＮ ＯＦ ＳＥＤＩＭＥＮＴ ＤＩＳＣＨＡＲＧＥ ＰＲＥＤＩＣＴＩＯＮＳ ＦＯＲ ＳＭＡＬＬ ＷＡＴＥＲＳＲＥＤＳ ＩＮ ＴＨＥ ＳＯＵＴＲＷＥＳＴＥＲＮ ＵＮＩＴＥＤ ＳＴＡＴＥＳＹａｋｏｖＷＩＧＤＯＲ；ＶｉｃｅｎｔｅＬ．ＬＯＰＥＳ... 相似文献
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IINTRODUCTIONItisveryoftentoobservegravelpericlesinformofimbricateclustersonmountainousriverbeds.Theparticleassemblagesareonaveragethreetosixparticlesinlengthandformassingle,highlyimbricatedlongitUdinalthreads.Theyneednotconsistofthelargestmaterialonthebed,eventhoughthisispredominantlythecase(DeJongandErgenzinger,1995).Theyaredifferentiatedintermsofshape,numberandarrangementofparticles,butmostlythelengthandthewidthoftheparticlesareafewtimesofthethickness.Willettsetal.(1982)investigatedt… 相似文献
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Based on the dimensional analysis, resistance coefficients of spherical particles to Bingham fluid in laminar flow region, transition region and fully developed turbulent flow regions are derived respectively. A systematical experimental study on settling velocity of steel balls in slurry with different sediment concentrations is conducted and comprehensive discussions are presented. Formulae proposed by the authors are checked with experimental data from various sources. 相似文献
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Limo TANG Shanghong ZHANG Mingzhong YU Xingkui WANG 《国际泥沙研究》2006,21(4):272-280
1 INTRODUCTION The mechanism of particle movement in the flow is one of basic problems of sediment transport research. The conventional measurement approaches usually disturb the structure of the flow, consequently inducing errors. With the development of… 相似文献
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Shengfa YANG Jiang HU Xingkui WANG 《国际泥沙研究》2006,21(3):220-229
1 INTRODUCTION To data, there are about 100 formulae for the incipient motion of sediment, among which, only about ten are convenient and practical. In 1936, using nondimensional drag force and the sediment’s Reynolds number, Shields (1936) presented the… 相似文献
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SHAO Xuejun XIA Zhenhuan ①Lecturer Deportment of Hydraulic Engineering Tsinghua University Beijing China ②Professor Department of Hydraulic Engineering Tsinghua University Beijing China 《国际泥沙研究》1991,(2)
The random motion of sediment particles suspended in a turbulent flow is studied by means of stochastic process. Results of analysis of particle's frequency response to the random force exerted on the particle due to fluid turbulence suggest that only the lower part of the whole frequency range of the eddy motion will govern the motion of the particle. The mean values of particle velocity and displacement in the vertical direc- tion are calculated and it is found that particle velocity vp- can be decomposed into a mean motion and a velocity fluctuation vp- , where is equal to the fall velocity in tranquil fluid. An Ito^ random differential equation for particle dis- placement Yp is developed, from which a Fokker-Planck equation for the probability density function p(y,t) is derived on the basis of the theory of Markov process, where y denotes the vertical coordinate. The vertical distribution of the particle is thus interrelated to the random motion of the particle. The an effect that a particle will be subject to in the neighborhood or the bottom boundary is taken into consideration and a corresponding Fokker-Planck equation is developed. Analytical solution of the Fok- ker-Planck equation including the lift force effect shows that probability density p(y,t) for the particle displacement has a maximum value at y = H where the perpen- dicular component of the lift force balances the particle gravity. This theoretical result agrees with experimental observations as reported in literature. 相似文献
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本文利用了小扰动方法、轨道法以及粒子的运动区域,比较系统地研究了带电粒子在中性线磁场中的运动。其结果是: 1.带电粒子的运动轨道可分为漂移轨道、波动轨道与8字形轨道三种形式。小扰动方法不能使用于中性线的区域内,在这个区域出现一个与小扰动漂移运动相反方向的运动。 2.在沿中性线方向的电场的作用下,中性线周围的部分粒子可以聚集到中性线附近。当粒子进入非小扰动区时,它们将被中性线磁场反射,并被电场加速。 3.计算出磁尾中性片的厚度为在这个区域内,大部分带正电的粒子的平均运动是沿晨昏方向,带负电的粒子的运动则相反。磁尾区出现一个等离子体中性片电流。 相似文献
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Trajectories and impinging action of spherical sand particles moving in the flows around a cylinder and in a plane cascade are calculated. Equations of motion, including more factors pertinent to the motion of particles, are applicable to flows at high particle Reynolds number. Erosion areas predicted from calcula- tion agree well with those from field observation in bydromachines. The results can also be used to estimate the intensity of erosion. 相似文献
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处于高纬向日面的极隙区是太阳风能量、动量和质量可以直接进入地球磁场并到达地球的近地空间的区域。本文简要介绍了极隙区的观测和研究，综述了极隙区的粒子沉降、场向电流、等离子体对流和电离层电流的特征。 相似文献
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EXPERIMENTAL STUDY ON INCIPIENT MOTION OF SEDIMENT PARTICLES ON GENERALIZED SLOPING FLUVIAL BEDS 总被引：3，自引：0，他引：3
Subhasish DEY Asst. Prof. Dept. of Civil Engrg. Indian Inst. of Tech. Kharagpur West Bengal India. Fax: + 《国际泥沙研究》2001,16(3)
1 INTRODUCTIONWhen water flows over a fluvial bed, hydro-dynandc force induced by the flow is acting on thesediment particles lying on the bed. A further increase in flow velocity results in an increase in themagnitude of this fOrce; and sediment particles begin to move if a situation is eventu8lly reached whenthe hydro-dynandc force exceeds a certain critical value. This initial movement of sediment pallicles istermed inciPient motion. The erosion and sedimentation of nuvial beds can be… 相似文献