| 1. | Choice of slit - type bucket parameters and estimation of scour hole depth 一级直线边墙窄缝挑坎参数选择与冲坑深度估计 |
| 2. | Scouring depth before the permeable pile dike reaches 20 m and the value increase with the upstream angle and flow rate of the coming flow 桩前冲坑最大深度可接近20m ,入流角和流量越大,冲坑越深。 |
| 3. | The relationship between the air concentration and the scour depth can be expressed as an exponential function . aeration does not affect the shape of scour hole 掺气浓度c _对冲坑深度的影响,可表达为掺气浓度与冲坑无量纲深度的幂函数关系。 |
| 4. | According to the similar rule , a movable bed model for downstream channel and the particle size distribution of the model silt in the channel and the scour hole are designed . a theoretical method of size distribution in the scour hole is devised 根据模型律设计了太平湾尾水渠动床模型,分别确定了河床中和冲刷坑中模型沙的配比,并对冲坑中的床质级配进行了理论推导。 |
| 5. | The formation of the scoured pits is related with such factors as the unstable flow velocity and the unstable flow state caused by the circumfluence in the cross direction , the upstream circumfluence and the circle flow around the embankment 冲刷坑的形成与横向环流、上游回流和绕流丁坝造成流速及流态不均匀等因素有关;根石走失与根石在水中的稳定性和河床性质及坝脚附近冲坑有关。 |
| 6. | For a single plunging jet , two optimization models are respectively introduced according to the jet trajectory distance and the depth of scour pool , and the optimal computation of the jet trajectory distance in xiao - wan project demonstrates that these models are reasonable ; 5 对于单股挑流消能水舌,以挑距和冲坑深度为控制目标,分别首次建立了优化数学模型,并通过对小湾拱坝单孔挑流水舌的计算,说明所提出的数学优化模型是可用的; 5 |
| 7. | ( 5 ) according to the calculated average section velocity . we can decide the type of the revetment . ( 6 ) when the scour hole depth of the dam head and trail parts is calculated inthe paper . we can validate whether the revetment material is strong enough to resist the degradation of the flood flow 根据以上计算所得的各断面平均流速,初步确定需要铺设的摘要护面类型计算在铺设护面以后坝首和坝末的冲坑深度,以验证护面材料是否可以抵抗洪水泄流的冲刷。 |
| 8. | The ratio of the length to the depth of scour hole decreases with the increasing scour depth , in spite of the reason is the increase of the air concentration , the decrease of the jet velocity or the decrease of the jet thickness . 5 . governing equations of the aerated jet flow are established 掺气对冲坑形态并没有实质性的影响,冲坑的宽深比随冲坑深度的减小而增大,无论造成冲坑深度减小的原因四) 1大学i学博士学位论文是掺气、降低流速还是减小入射水舌厚度,其变化规律都可用相同的直线关系表示。 |
| 9. | The main contents and conclusions are as follows : 1 . the dynamic pressure on the original riverbed and the scour hole are measured . the results show that the characteristics of dynamic pressure in the scour hole are the same as that on the original riverbed 表明在基岩冲刷过程中以及冲坑稳定后,射流冲击区的脉动压强与冲坑形成前一样,都是以低频大振幅为主,说明在冲刷坑形成后,射流冲击区水流与无冲坑时一样,都是大尺度涡不断破碎和小尺度涡不断生成的过程。 |
| 10. | Hongjiadu hydraulic power plant is the only leading water storage reservoir of wujiang cascade hydraulic stations , which is a full - time storage reservoir . 2 * landslide body is distributed at the right side of downstream , which is just located in the region of energy dissipation . erosion gully may cut the bottom of the landslide body . there are roads on the top of the landslide body during the construction period and operating period 洪家渡水电站是乌江梯级水电站中唯一具有多年调节性能的“龙头”水库, 2 #塌滑体分布于坝址下游右岸,恰好位于泄洪消能防冲区内,冲坑将塌滑体下部切脚,而且施工期和运行期在其上都布置有公路,因此2 #塌滑体失稳将影响整个水电站的正常运行。 |