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1.
Conclusions The capacity of a structure operating as a broad-crested spillway can be significantly increased, if the entrance and, especially, the outlet widths are increased, which for the same spillway length c and contraction width Bkey leads to a reduction of the ratio Bkey=Bkey/B and at the same time to an increase in the flow capacity of the structure. Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 6, pp. 42–44, June, 1967.  相似文献   

2.
台阶式溢洪道因其显著的消能、掺气效果而倍受工程界的关注.在许多试验研究的基础上,提出了台阶式泄槽溢洪道泄槽及降低护坦式消力池的水力计算方法.台阶式溢洪道泄槽的设计主要包括泄槽倾斜角度、台阶高度和长度确定、泄槽边墙高度确定、台阶上的压强计算及防空蚀破坏措施的确定3部分.尽管台阶式溢洪道受到世界各国水利界人士的强烈关注,并进行了大量的试验研究,但目前对于台阶式溢洪道的系统计算方法研究尚未看到报道,因此,对台阶式溢洪道系统计算方法的研究具有重要的现实意义.  相似文献   

3.
1.  For hydrodevelopments located on mountain rivers with a narrow, tortuous channel deeply incised into the rock, the problem of providing a maximum range of ejection of the flow and simultaneously eliminating its considerable effect on the canyon slopes in the case of a dam spillway with a frontal ski-jump is quite complex. Variants with a spillway tunnel ending with a lateral overflow ski-jump are considerably more flexible.
2.  The use of a lateral overflow ski-jump and uniformly distributes the discharges over a sufficiently long stretch of the channel and eliminates the fall of large quantities of water onto the canyon slopes through a wide range of discharges and heads. In this case the intensity of the effect of the discharge on the channel bed can be reduced substantially in comparison with the frontal ski-jump.
  相似文献   

4.
巴贡水电站地处降雨量充沛的热带岛屿,枢纽中有1座202 m高的混凝土面板石坝、陡槽溢洪道、放水隧洞和水电厂。溢洪道下泄流量大,落差大,泄水冲沟对施工干扰大,施工道路及设备布置困难。针对施工中的难点制定了施工方案,重点论述其中的道路规划、设备布置、模板选型及混凝土浇筑方案等。  相似文献   

5.
高陡槽溢洪道挑流鼻坎体形研究   总被引:1,自引:0,他引:1  
结合紫坪铺水利枢纽工程的溢洪道挑坎特性,采用模型试验的研究方法,根据挑流鼻坎体型设计理论和它灵活性特点,应用CFX软件对挑流鼻坎体型进行了改进优化,以使挑流水舌分布更均匀、挑距更大和冲刷更小,并通过对水舌和冲坑特性的观测来验证改进结果。  相似文献   

6.
1.  The substantial characteristic of the flow regime in an antiwhirl dissipator (AWD) is the presence in it of a region of significant dimensions, the pressure in which reaches the limit of the physically possible vacuum under these conditions, that is, the vaporization pressure.
2.  Supply of air in the quantity required for elimination under these conditions of the risk of development of cavitation (taking into account the pressure pulsations) substantially reduces the effectiveness of the AWD as an energy dissipator.
3.  The air flow required for protection against intense cativation erosion of a series of AWD zones should be limited by the discharge capacity of the air-feed system, characterized by the value μw=1.2 m2. In this case the averaged pressure drop in the air conduit may reach 6–7 m of water column, which corresponds to a supersonic velocity (about 400 m/sec, that is, more than five times the value usually permitted for aeration shafts). Under such velocities gasodynamic effects are possible (compression jumps, decrease of the discharge capacity, strong sonic phenomena), which call for special investigations.  相似文献   

7.
分析了寺坪枢纽溢洪道泄槽底板水损的原因以及所选取修复方案。  相似文献   

8.
陡槽式溢洪道三维流场数值计算分析   总被引:1,自引:0,他引:1  
陡槽式溢洪道是一种广泛使用的泄水建筑物,它直接影响水利枢纽防洪调度和安全运行,对其水流全场水力特性的全面研究具有重要意义.采用RNGk~ε双方程模型模拟湍流,利用流体体积分数法(VOF)确定自由水面线,笛卡尔自适应网格与部分面积体积障碍模拟法(FAVOR)处理复杂的几何边界,成功地对大伙房水库陡槽式主溢洪道流场进行了三维紊流数值模拟,得到了自由水面、溢洪道堰面压力、断面流速大小、分布和三维流场的分布规律,表明数值模拟与物理实验结果两者吻合较好.  相似文献   

9.
为提高大单宽流量阶梯溢洪道消能率和增加掺气,提出一种新型反弧阶梯溢洪道,即将传统直角阶梯的水平面改为反弧面。通过物理模型试验,对反弧形阶梯的流态、掺气发生位置和消能率进行了研究。结果表明,在试验条件范围内,反弧阶梯流态可分为跌落流、挑射流、过渡流、滑行流4 种,在单个阶梯长度和高度相同时,反弧阶梯掺气发生位置是直角阶梯的0. 5 ~0. 8 倍,反弧阶梯消能率比直角阶梯最大增加约9%。  相似文献   

10.
通过引子渡水电站溢洪道消能防冲试验研究 ,从消能防冲角度提出了大流量、宽浅式挑流消能溢洪道泄槽及消能工体型设计的较优方案 ,可为同类工程的设计参考。  相似文献   

11.
庄荣文 《水利学报》1996,(9):27-32,37
本文建立设计连续式挑流消能工坎高和坎角的多目标优化数学模型,并讨论其优化计算方法,通过算例验证表明,利用这一模型所设计的连续式挑流坎的坎高和坎角,可一定的流量范围内取得综合最优的消能效果。  相似文献   

12.
在坡度i=1∶2-1∶6的的陡槽溢洪道外凸式阶梯消能工水力模型试验基础上,对不同阶梯体型的陡槽段水力特性进行研究探讨。根据阶梯陡槽段泄流特性,将阶梯陡槽段泄流分为光滑水流和掺气水流两区段,并将掺气水流区段又分为不均匀流段、准均匀流段、末级阶梯至陡槽末端不均匀流段等三个流段。该文提出了阶梯陡槽段各区段和流段水深的计算公式,其研究成果可供溢洪道阶梯陡槽段沿程水面线和消能计算参考。  相似文献   

13.
为了对比研究不同整流措施对弯道流态的改善效果,本文通过数值模拟方法建立了无措施、布置导流墙、丁坝、斜底槛四种模型,通过模拟结果可以发现布置导流墙后,可以减小弯道水流惯性力,流态得到一定改善.布置丁坝后流态较导流墙效果不明显,但主流区被导向凸岸,对凸岸具有一定防冲刷作用.布置斜底槛后,下游的左右岸水力要素分布均匀,而且旋涡较多,具有导流与消能的双重作用.  相似文献   

14.
糯扎渡水电站溢洪道泄槽流激振动试验研究   总被引:1,自引:0,他引:1       下载免费PDF全文
通过水弹性模型试验,研究糯扎渡水电站溢洪道泄槽隔墙通过宽大的F1和F3断层时的流激动力响应,并对其安全性进行评估。试验结果表明,糯扎渡水电站溢洪道泄槽隔墙模型实测基频分别为9.86Hz(干模态)及9.28Hz(湿模态),隔墙顶部最大泄洪振动响应发生在低泄量工况,其动位移均方根值达105.5μm。根据Meister感觉曲线可知,处于微有感觉或相当有感觉状况。隔墙的最大动应力振幅(3σ)为0.141MPa,可以认为隔墙在溢洪道正常泄洪时不会发生疲劳破坏。  相似文献   

15.
16.
Conclusions  
1.  A method was developed for calculating the average cross-sectional flow velocities over the length of a fishholding chute.
2.  PC programs were developed which are recommended to be used when calculating and designing fishways with continuous delivery of water along the length of the fish-holding chute.
3.  Experimental data characterizing the projections of the total velocities of the added (detached) mass onto the direction of the velocity of the main flow were obtained. Experiments established that for the given problem the values of the varying mass coefficientsn do not change over the length of the fish-holding chute and do not depend on the character of the permeable barrier or investigated relations of the hydraulic and geometric parameters. The values ofn for calculating the hydraulic regimes should be taken within 0.145 and 0.160.
4.  At the initial time of its movement toward the working chamber the stimulating device should be placed at a certain distance from the entry. This distance is calculated by the programs developed for a PC. Movement of the stimulating device leads to a change in the character of the addition and separation of discharges between the galleries and chute. This provides favorable hydraulic regimes in the fish-holding chute for the fish species being passed.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 3, pp. 50–53, March, 1997.  相似文献   

17.
巴贡水电站地处热带岛屿,降雨量充沛,其中溢洪道地处陡峭地势,左岸冲沟泄水对施工干扰大,施工道路及设备布置困难;同时溢洪道水流下泄落差大、流速高(达47 m/s),对过流面平整度要求高。而且,溢洪道泄槽墙体狭长单薄,施工难度大,工期紧张等,具有其他泄槽施工所无法比拟的困难。针对上述施工中的难点,对道路规划,模板选型,设备布置及混凝土浇筑等几个方面作了较深入的论述,旨在供同类工程借鉴。  相似文献   

18.
开敞式宽大单泄槽溢洪道与一般溢洪道相比易发生水流流态复杂、掺气效果差等工程安全问题。以马来西亚Baleh水电工程为例,采用VOF法与RNG k-ε双方程紊流模型对溢洪道流场进行三维数值模拟。计算分析了不同工况下溢洪道流态、流速、沿程压强等水力特性的分布规律。同时开展1∶50物理模型试验,对比分析数值模拟结果与模型试验结果发现,两者基本一致,验证了开敞式宽大单泄槽溢洪道水力特性数值模拟的准确性与可行性。进而利用紊流模型计算分析了溢洪道掺气坎的优化布置方案,结果表明:1#掺气坎抬高20 cm后,坎后掺气空腔长度由11.03 m增大至19.84 m,消能率提高了6.11%;3#掺气坎沿泄槽陡坡上移15 m后,挑流水舌冲击位置上移,减轻了对挑流鼻坎段水流流态的影响。研究结果对同类工程的优化设计有一定的借鉴作用。  相似文献   

19.
水利枢纽溢洪道掺气坎槽体型研究   总被引:3,自引:0,他引:3  
结合糯扎渡水利枢纽溢洪道掺气减蚀模型试验研究,根据试验资料,利用回归分析,拟合出关系曲线,建立了坎高与水深、流速、溢洪道底坡、挑坎挑角关系的经验公式,并通过已建成的工程实例来验证公式的实用性.该公式对掺气坎槽选型提供了依据,可供设计与模型试验阶段参考。  相似文献   

20.
竖井孔板泄流消能塔的水力与振动试验   总被引:2,自引:0,他引:2  
简述了导流洞改建为永久泄洪洞时的不同消能方案和井式溢洪道的特点,给出了竖井与多级孔极组合式泄流消能塔的水流与振动试验实例,振动试验时模拟了塔基的力学特性,具体试验虽是针对一尾矿坝进行的,但这种结构形式和试验结果对水利工程设计也有一定参考价值.  相似文献   

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