反坡正弦波形底板上F型水跃水力特性的试验研究

Experimental study on hydraulic characteristics of F-type jumps over adverse-sloped sinusoidal corrugated beds

  • 摘要: 试验研究了3个相对粗糙度(0.51、0.86、1.34)和6个坡度(−0.02、−0.03、−0.04、−0.05、−0.07、−0.10)对反坡正弦波形底板上F型水跃水力特性的影响。在弗劳德数从5到11的范围内,总共进行了57次试验。试验结果表明:与经典水跃和光滑底板上的F型水跃相比,反坡正弦波形底板能有效减小漩滚长度和共轭水深比,粗糙底板有利于稳定F型水跃。剖面速度分布对相对粗糙度比反坡坡度更敏感,坡度和相对粗糙度影响速度剖面的相似性和边界层厚度的发展。在距离F型水跃起始点40%漩滚长度附近,剖面速度分布最不均匀;在1.2倍的漩滚长度后,剖面动量修正系数基本上都接近1.0。反坡正弦波形底板的综合剪切应力系数是水平光滑床的10~16倍,这表明反坡正弦波形底板在短距离消能方面非常有效。

     

    Abstract: In this study, a total of 57 tests were performed to investigate the effects of three relative roughnesses (0.51, 0.86, 1.34) and six slopes (−0.02, −0.03, −0.04, −0.05, −0.07, −0.10) on the hydraulic characteristics of F-type jumps over adverse-sloped sinusoidal-corrugated beds, whose Froude Number ranged from 5 to 11. The experimental results show that compared to the classic hydraulic jump and the F-type jump on the smooth bed, the adverse-sloped sinusoidal-corrugated bed can effectively reduce the roller length and sequent depth ratio. And the rough bed is beneficial to stabilize the F-type jump. The velocity profiles are more sensitive to the relative roughness than the slope, and the relative roughness affects the similarity of these velocity profiles and the development of boundary layer thickness. The velocity profile is most uneven near 0.4 times roller length away from the initial point of the F-type jump. After 1.2 times the roller length, the momentum correction coefficient of the profile is almost 1.0. The shear force coefficient of the adverse-sloped corrugated bed is 10~16 times that of the horizontal-smooth bed, which indicates that the adverse-sloped sinusoidal-corrugated bed is very effective in energy dissipation over short distances.

     

/

返回文章
返回