水力坡度对淹没单丁坝近区水流结构的影响

发布时间：2018-03-21 16:21

  本文选题：水力坡度　切入点：淹没单丁坝　出处：《水利水运工程学报》2017年02期 　论文类型：期刊论文

【摘要】：采用超声波水位和PIV流速测量技术,在U形水槽中试验研究了不同水力坡度下淹没单丁坝对水流的影响。同一水力坡度,丁坝上游横比降沿程逐渐增大,丁坝下游横比降沿程逐渐减小。不同水力坡度,随着水力坡度的增大:1丁坝附近的水位、横比降、淹没程度和丁坝迎水面与背水面的水位差逐渐减小;2丁坝上游最高水位位置向下移动,丁坝下游水位恢复点位置向上移动;3断面平均流速及最大流速逐渐增大,但最大流速出现的位置基本不变;4漩涡流速分布较相似,但漩涡强度增加,坝后漩涡中心逐渐向下游对岸移动。当水槽坡度为-1‰~1‰时,淹没丁坝对丁坝上方5 cm处的剖面水流影响较小;当水槽坡度为2‰时,淹没丁坝对丁坝上方5 cm处的剖面水流影响较大;当水槽坡度为1‰~2‰时,淹没丁坝对水流结构的影响可能存在1个临界变化点。研究结果有助于对河床演变及海岸工程等复杂水环境问题的深入探索。
[Abstract]:By using ultrasonic water level and PIV velocity measurement technique, the influence of submerged monolayer on water flow under different hydraulic slopes was studied in U-shaped flume. The lateral ratio of the spur dike decreases gradually. With the increase of the hydraulic gradient, the horizontal ratio decreases with the increase of the hydraulic gradient near the water level near the dike, The submergence degree and the water level difference between the facing surface and the back surface of the spur dike gradually decrease and the maximum water level position moves downward in the upper reaches of the second spur dike, and the average velocity and the maximum velocity of the section are gradually increasing when the position of the recovery point of the downstream water level of the spur dike moves upward. However, the position of the maximum velocity is almost the same, but the swirl intensity increases, and the center of the vortex moves to the downstream shore gradually. When the gradient of the flume is 1 鈥，

本文编号：1644619