宽尾墩对官地水电站底流消能影响的试验研究

针对官地水电站进行了有、无宽尾墩的局部模型试验研究,从堰面及消力池内流态、消力池内水面线、堰面和消力池底板时均压强和脉动压强的沿程分布、消力池内临底流速沿程分布等方面详细地分析了宽尾墩对底流消能的影响。试验结果表明:宽尾墩改善了官地水电站底流消力池内的水流流态,能降低消力池底板上的时均压强和脉动压强,改善了跌坎下的流速分布和流速梯度,有利于解决官地水电站大落差、高流速、大单宽流量的泄洪消能问题。     

宽尾墩对跌坎底流消能影响的试验研究

针对跌坎底流消能在下游水位变幅较大的电站中的泄流消能问题,结合赛格电站进行了模型试验研究,从消力池的水流流态、临底流速以及底板时均冲击压力三方面详细地分析了宽尾墩对跌坎底流消能的影响。试验结果表明,宽尾墩改善了跌坎底流消力池内的水流流态,降低了消力池内的临底流速和时均压力,较好地解决了跌坎底流消能不能适应下游水位变幅较大这类工程的泄洪消能的缺陷。     

宽尾墩对跌坎底流消力池影响的试验研究

针对低水头、大单宽流量、下游水位变幅大的水电站中的泄洪消能问题,本文结合官地水电站工程进行了水工模型试验研究,从消力池的水流流态、临底流速以及底板时均动水压强对比几方面,分析了宽尾墩对跌坎底流消力池的影响。结果表明,宽尾墩改善了消力池内的水流流态,降低了消力池内的临底流速和时均压强,充分利用了宽尾墩技术优势,提高了泄洪设施的总消能率,有效解决了下游水位变幅较大的水电工程类泄洪消能问题。     

阿尔塔什水利枢纽工程底流消力池临底流速及体型优化试验研究

通过阿尔塔什工程1#深孔的单体水工模型试验,研究了消力梁、消力墩、尾坎底高程、尾坎位置、消力池底板高程、跌坎等对消力池中线临底流速沿程分布及最大临底流速的影响。结果表明:消力梁和消力墩均能降低消力池最大临底流速,消力墩对临底流速的影响大于消力梁;降低尾坎高程或尾坎前移都会导致消力池最大临底流速增大;加设跌坎或降低底板高程均能减小消力池最大临底流速,降底底板高程、加设跌坎的消力池体型的最大临底流速相比于原设计体型降幅相当。综合考虑消力池临底流速及其他指标,在原来设计体型的基础上,消力池底板高程降2 m方案合理。     

宽尾墩-跌坎型底流联合消能工水力特性试验研究

通过水工模型试验着重分析比较了宽尾墩-跌坎联合消能工与跌坎以及常规消能工消力池内的水流流态、临底流速以及脉动压力等,并根据试验结果拟合分析了该联合消能工的强迫水跃长度公式。试验结果表明,该种新型的消能方式改善了跌坎消力池内的水流流态,降低了消力池内的临底流速和脉动压力,缩短了消力池的长度,减轻了下游河道的冲刷,并且能很好地利用宽尾墩良好的消能率,克服宽尾墩挑射水流对消力池底板的冲击问题,为类似工程提供了参考,同时也丰富了泄洪消能工的型式。     

跌坎对消力池水力特性影响的试验研究

为研究跌坎在底流消能中的作用,依托某工程水力学模型,研究了跌坎对消力池内水流流态、临底流速及脉动压强的影响。结果表明:在来流量一定的情况下,随着跌坎高度的增加,消力池内流态会由底流依次演变为淹没混合流及淹没面流流态。加设跌坎可显著降低消力池前半段的临底流速,且跌坎越高,最大临底流速降幅越大,跌坎对消力池后半段的临底流速基本无影响;跌坎对脉动压强影响较大,随跌坎高度的增加,最大脉动压强先增大后减小;加设跌坎后,脉动压强和临底流速沿程先增大后减小,且脉动压力和临底流速的最大值位置基本在同一区域。     

跌坎型消力池与Y形宽尾墩联合消能试验研究

牙根二级水电站具有高水头、大流量、窄河谷的特点,结合其底流消能进行了模型试验研究。通过反弧末端加设跌坎,降低了消力池的临底流速,对不同的跌坎高度进行比较,总结了跌坎池深比对淹没水跃的影响。通过表孔加设Y形宽尾墩,进一步降低脉动压力和临底流速,增强了消能效果,为工程设计提供了有力支持。     

连续跌坎型底流消能工水力特性的影响因素研究

通过大量的试验,测量了消力池底板压强分布规律、池内流态和流速分布,着重分析了入池水流单位重量水体能量、入池角度和跌坎高度的变化对消力池底板冲击压力、临底流速、池内流态及消能率的影响。研究表明,连续跌坎型底流消能工的跌坎高度与入池角度之间存在一种最优组合,可既保证消力池中消能率高,又能满足临底流速和底板动水冲击压力小的要求。该研究成果可为工程设计提供一定的科学依据。     

跌坎深度对扩散式泄槽底流消能水力特性影响试验研究

对于高水头泄水建筑物而言,为了降低出口单宽流量,减轻下游消能压力,通常在出口设置扩散式泄槽。突扩式底流消力池增设跌坎,可避免水流直接冲击消力池底板,降低底板力学指标。通过水工模型试验,基于一定的边墙突扩宽度,研究突扩式消力池在不同跌坎深度下底板临底流速、时均压强、脉动压强的变化。成果表明:跌坎深度为5 cm时,消力池内水流流态介于临界水跃向远驱式水跃过渡区间,临底流速最大,时均压强最小;跌坎深度增加至10 cm时,消力池能够形成稳定的淹没水跃,临底流速明显减小,时均压强明显升高;跌坎深度进一步增加至15 cm时,消力池内淹没程度继续增加,临底流速继续减小,时均压强继续增加,但变幅均不大。     

跌坎式底流消能工的消能机理分析与研究

对比常规的底流消能工，对跌坎式底流消能工消能水力特性进行了分析和试验研究。通过对底流消能机理的分析、平面紊动射流的流速分布和对比模型的对比试验，分析了消力池中的水流运动状态和跌坎在消力池中的作用。利用跌坎式底流消能，可大大降低临底流速，减小消力池底板上的脉动压强，增加淹没射流消能效果和水流的平稳，减小雾化对周围环境的影响，是一种有效的新型消能方式。     

Tastes associated with products in contact with drinking water.

Over the past 9 years the Australian Water Quality Centre (AWQC) has conducted testing in accordance with Australian and New Zealand Standard AS/NZS 4020--"Products for use in contact with drinking water" (1999). A test included as part of this standard is taste of water extracts. This test assesses the ability of products to impart discernible taste to drinking water using panellists trained in accordance with Standard Methods for the Examination of Water and Wastewater--Flavour Profile Analysis 2170 B (1999). Over 1000 products from companies worldwide, have been assessed at the AWQC in accordance with AS/NZS 4020 including pipes, valves, tap fittings and numerous other products used in contact with water. The products must not impart any discernible taste to obtain compliance and be deemed suitable for use in contact with drinking water. This study compiles the products assessed and the types of tastes obtained from both chlorinated and non-chlorinated extracts. In particular the study focuses on taste associated with polyethylene pipes, coatings and valves, which in some instances have been problematic. Analysis revealed that most taste problems occur when chlorinated water has been used in extraction experiments and this is in line with consumer complaints regarding taste imparted by plumbing products. The collation of this data provides a valuable assessment for manufacturers, the water industry and consumers.     

大尺度水文模型及其与气候模型的联结耦合研究

本文综述陆地表面水文过程，大尺度水文模型及其与气候模型联结耦合研究的最新进展和存在问题。介绍ＧＥＷＥＸ－ＧＡＭＥ研究项目的目标和内容，科学价值和现实意义及其在我国开展研究的计划。     

不同改性膨润土处理染料废水的实践

钙基膨润土经不同的改性,可用来处理染料废水.分析比较了不同改性后的膨润土处理染料废水的效果.处理效果由强到弱,依次是柱撑酸化膨润土、柱撑膨润土、酸化膨润土、酸化柱撑膨润土、钠化膨润土、钙基膨润土.     

Hydrological daily rainfall-runoff simulation with BTOPMC model and comparison with Xin'anjiang model

A grid-based distributed hydrological model, the Block-wise use of TOPMODEL (BTOPMC), which was developed from the original TOPMODEL, was used for hydrological daily rainfall-runoff simulation. In the BTOPMC model, the runoff is explicitly calculated on a cell-by-cell basis, and the Muskingum-Cunge flow concentration method is used. In order to test the model's applicability, the BTOPMC model and the Xin'anjiang model were applied to the simulation of a humid watershed and a semi-humid to semi-arid watershed in China. The model parameters were optimized with the Shuffle Complex Evolution (SCE-UA) method. Results show that both models can effectively simulate the daily hydrograph in humid watersheds, but that the BTOPMC model performs poorly in semi-humid to semi-arid watersheds. The excess-infiltration mechanism should be incorporated into the BTOPMC model to broaden the model's applicability.     

Coping with Hydrological Extremes

Abstract

Coping with hydrological extremes, floods, and droughts has been a major concern since the dawn of human civilization. Freshwater, a necessary condition of life and a raw material used in very high volumes in virtually every human activity, is becoming increasingly scarce. Water use has risen considerably in the last hundred years at a pace exceeding the population growth. Therefore, societies are increasingly vulnerable to droughts and water deficits. Although the 21st century is heralded as the age of water scarcity, flood losses continue to grow. Increasing global vulnerability results to a large extent from soaring anthropopressure: settlements in hazardous locations and adverse land use changes. Deforestation and urbanization lead to reduction of the storage volume and higher values of runoff coefficient. In more wealthy countries, it is the material flood losses that continue to grow, while the number of fatalities goes down. Advanced flood preparedness systems can save lives and reduce human suffering. In some regions of the world, long-term forecasts (e.g., ENSO) help improve the preparedness for hydrological extremes, both floods and droughts, and hopefully will even more so in the future. Scenarios for future climate indicate the possibility of sharpening the extremes and changes of their seasonality. For instance, in Western Scotland and Norway, an increase of winter floods has already been observed. According to recent assessments, there is a growing risk of summer droughts in the Mediterranean region: less precipitation in summer and higher temperature will coincide, causing higher evapo-transpiration and less runoff. Fighting with floods and droughts has not been quite successful. Humans have to get used to the fact that extreme hydrological events are natural phenomena that will continue to occur. While doing one's best to improve the preparedness systems, it is necessary to learn to live with hydrological extremes.     

Spillway with nappe aeration

Conclusion Investigations showed that aeration of the flow by jump-off aerators is a simple, reliable, and economic means of protecting the overflow surface against cavitation erosion or suppressing it on an operating structure. Flow aeration can be regulated by the size of the jump-off aerators and change of the capacity of the air-supply system. Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 5, pp. 16–20, May, 1973.     

只以今生续画缘

此生能够画画并以此为业,可算是与画有缘。对画画感兴趣可能是大多孩子的爱好。余少时亦能在乡贤教诲下描摹动物、鞍马、人物,那也只不过是一种儿时的游戏。延伸下来慢慢地竟成了养家糊口安身立命的职业,可以说这真的是一种幸运,可谓与画有缘。