助手标题  
全文文献 工具书 数字 学术定义 翻译助手 学术趋势 更多
查询帮助
意见反馈
   high-dam 的翻译结果: 查询用时:0.169秒
图标索引 在分类学科中查询
所有学科
水利水电工程
更多类别查询

图标索引 历史查询
 

high-dam
相关语句
  高坝
     A Engineering Geological Feasibility Study of High-dam Construction Project at Site with Complicated Geological Conditions
     复杂场地高坝建设适宜性的工程地质研究
短句来源
     New Development of High-dam Navigation Technology in the Shuikou Hydro Project
     高坝通航技术在水口工程的新发展
短句来源
     Engineering geological feasibility study is a key stage to high-dam construction.
     研究复杂地质环境条件下高坝建设的适宜性是水电工程建设过程中不可或缺的一个重要环节。
短句来源
     With more and more internal and external high-head conservancy projects constructed,finding a new dissipation method for solving the problems of outlet structure's safety and dissipation under the condition of high-head and large discharge is one of the hard nuts to crack having to be settled urgently during high-dam hydraulic design.
     随着国内外高水头水利枢纽工程的日益兴建,寻求新的消能途径解决高水头大流量条件下泄水建筑物的安全和消能问题是高坝水力设计中亟待解决的难题之一。
短句来源
     おhis paper presents the study purpose and meaning of the high-dam flood-relief energy-dissipation aerial water-jet nappe flow velocity;
     本文介绍高坝泄洪消能空中挑射水流流速研究的目的和意义;
短句来源
  相似匹配句对
     high vvearability.
     耐磨性高.
短句来源
     the value of E was high;
     反应活化能较高;
短句来源
     O - resistance is high.
     后者化验:血沉明显增快,抗“O”增高。
短句来源
     high-technology;
     产业高技术化;
短句来源
     Jog to the Dam
     慢跑到水坝去
短句来源
查询“high-dam”译词为用户自定义的双语例句

    我想查看译文中含有:的双语例句
例句
没有找到相关例句


To be able to locate the point of inception of air entrainment is of considerable significance in the design of ski-jump spillways for high dams, in that this is not only prerequisite to the theoretical analysis of jet diffusion in the air and the subsequent alleviation of erosion as the aerated jet dives to the bed, but also essential if the possible benefit of aeration in the reduction of concrete pitting is to be evaluated. Although past contributions to this problem are numerous, no method has yet been available...

To be able to locate the point of inception of air entrainment is of considerable significance in the design of ski-jump spillways for high dams, in that this is not only prerequisite to the theoretical analysis of jet diffusion in the air and the subsequent alleviation of erosion as the aerated jet dives to the bed, but also essential if the possible benefit of aeration in the reduction of concrete pitting is to be evaluated. Although past contributions to this problem are numerous, no method has yet been available to yield the correct prediction of the onset of aeration in or downstream of the curvilinear portion of the spillway which is known to take place much earlier than usual. Even for the straight portion of the spillway, calculated positions of aeration inception do not always match with the observed values (see table 1, and compare columns 4 to 7). In this paper is presented a rational and yet rather simple procedure with which one may treat the general problem of locating the position of aeration inception no matter if the spillway contains a curve or not. In the first place, the irrotational or "ambient" flow outside of the boundary layer is studied. In view of the fact that the flow over the spillway of a high dam is much smaller in extent laterally than longitudinally, an approximation similar to that used in the derivation of boundary layer equations from the Navier-Stokes equations is applied to the Euler equations. The resulting expressions indicate that the usual assumption of concentric streamlines is justifiable. The depth of flow is taken as that so calculated plus the displacement thickness of the boundary layer. Since on the plane of the complex potential, the flow over a spillway may be formulated as a simply-mixed boundaryvalue problem, Wood's exact method is applied to a numerical example with gravitational effect taken into consideration. The result of calculation indicates that both methods yield practically the same depth of flow. The inception of aeration is, as usual, assumed to occur as the boundary layer meets the free surface. Under the combined influence of gravity and boundary geometry, the flow over a dam is continuously accelerated or decelerated. In such case, boundary-layer computation by usual method is both involved and of doubtful accuracy. It is found, however, that in the case of flow over a spillway, the flow outside of the turbulent boundary layer conforms to a condition of self-preservation as proposed by Townsend. Since the Reynolds number for high dams may surely reach very high values, the turbulent boundary layer itself may be assumed to be approximately self-preserving. In short, this means that Townsend's theory of approximate self-preservation for boundary layers under the influence of longitudinal acceleration may be applied. This also means that the computation of boundary layer development may be much simplified. Based on an analysis of prototype data, it is found that in the present case involving air-entrainment inception, thickness of the boundary layer should be defined as that at which the mean velocity is within 0.1% of the velocity of flow outside the boundary layer. In the carrying out of the computations, boundary layer thickness at various sections are first estimated, then the irrotational flow outside the boundary layer is analysed by the simplified method to obtain the surface profile and the parameter "a" denoting the variation of velocity along the surface, and finally Townsend's theory of approximate self-preservation is applied to recompute the thickness of the boundary layer along the spillway. As any error made in the estimation of boundary-layer thickness has little effect on the computation of surface profile and hence on any subsequent computations, reasonably experienced computers should find it unnecessary to repeat the computations. Results of computations are found to be within 10% of the observed data obtained at two dams.

鉴于现有掺气发生点的计算方法误差可达观测值的70%以上,本文根据原型掺气发生点观测资料探讨较准确的计算方法,在无特殊干扰的条件下,掺气的发生取决于紊流边界层的发展.坝面边界层流动的特点是:雷诺数高(u_1x/,v在10~8至10~(10)之间),坝面粗糙,和水流先加速后减速因而纵向流速梯度对边界层发展的影响必须考虑.针对这些特点和坝面及陡槽高速水流具有自模性质,本文建议应用自模理论进行计算.计算的掺气点位置与实测位置比较误差减至10%左右,从而为掺气发生点或坝面紊流边界层的计算提供了较可靠的方法.

The paper describes the compaction characteristics of clayey soil. In view of the basic conception that the optimum degree of saturation Srop under various compaction energy is constant, and the optimum moisture content of the standard compaction energy is approximately the plastic limit, a method by using plastic limit wP and optimum saturation for estimation of the maximum dry density is presented as follows:γdmax=Srop·G3/G3wp+Sropwhere G3 is the specific gravity of the soil particles,wP is the plastic limit.Methods...

The paper describes the compaction characteristics of clayey soil. In view of the basic conception that the optimum degree of saturation Srop under various compaction energy is constant, and the optimum moisture content of the standard compaction energy is approximately the plastic limit, a method by using plastic limit wP and optimum saturation for estimation of the maximum dry density is presented as follows:γdmax=Srop·G3/G3wp+Sropwhere G3 is the specific gravity of the soil particles,wP is the plastic limit.Methods of determining the compaction criterion of clayey soil are discussed and the coefficient of construction m is introduced and demonstrated with suggestion value 0.95~0.97 for medium and low dams, and 0.97~0.99 for high dams.

本文总结了粘性土的压实特性,从不同击实功能下土料的压实最优饱和度S_(rop)为常数、标准击实功能的最优含水量ω_(op)约等于塑限ω_p这些基本概念出发,提出了用塑限、最优饱和度来估算粘性土的最大干容重γdmax。即S_(rop)=C,W_(op)=ω_p且当W_p≤17%,S_(rop)=(3ω_p+35)%ω_p>17%,S_(rop)=(0.3ω_p+80)%γdmax=(Gs·S_(rop))/(Gs·ω_p+S_(rop))在文中讨论了确定粘性土压实标准的方法,并对施工条件系数m进行了论证,提出了建议数值。即对于中低坝:m=0.95~0.97对于高坝:m=0.97~0.99

A curve of equal cavitation number ( abbreviated as ECN curve ) is proposed for buckets of high-dam spillways. Based on simplified analysis, equations for the calculation of such a curve have been developed. These equations may be conveniently solved by a Runge-Kutta scheme. Applications to high-dam spillways show that the effective head of a spillway as far as cavitation potential is concerned may be materially reduced by adopting the ECN curve for the bucket. In one case, the effective head of...

A curve of equal cavitation number ( abbreviated as ECN curve ) is proposed for buckets of high-dam spillways. Based on simplified analysis, equations for the calculation of such a curve have been developed. These equations may be conveniently solved by a Runge-Kutta scheme. Applications to high-dam spillways show that the effective head of a spillway as far as cavitation potential is concerned may be materially reduced by adopting the ECN curve for the bucket. In one case, the effective head of a spillway with a drop of 111.5m is thus reduced to 62m.

本文给出了等空化数线的计算方程和应用龙格——库塔法的计算框图。采用等空化数线反弧可使最小泄洪空化数显著提高。

 
<< 更多相关文摘    
图标索引 相关查询

 


 
CNKI小工具
在英文学术搜索中查有关high-dam的内容
在知识搜索中查有关high-dam的内容
在数字搜索中查有关high-dam的内容
在概念知识元中查有关high-dam的内容
在学术趋势中查有关high-dam的内容
 
 

CNKI主页设CNKI翻译助手为主页 | 收藏CNKI翻译助手 | 广告服务 | 英文学术搜索
版权图标  2008 CNKI-中国知网
京ICP证040431号 互联网出版许可证 新出网证(京)字008号
北京市公安局海淀分局 备案号:110 1081725
版权图标 2008中国知网(cnki) 中国学术期刊(光盘版)电子杂志社