The Hydraulic Characteristics Of The Flow In Stepped Spillway With Slopes

Stepped spillway has many merits; it was used more and more in hydraulic engineering in the past20years, while, in order to its scope of application adapted to the large unit discharge, the problem was solved the steps surface cavitations damage, in-depth study of stepped spillway aeration, especially non-uniform pressure characteristic is particularly important..In this paper, it is mainly studies hydraulic characteristics on the stepped spillway with slope. The main research results are as follows:(1) Test showed that the slope is slowing down, the initial step ladder spillway significant contracted section, followed by water surface profile gradually increased, the water surface profile has no changed in fresh water flood district, afar the aerated inception point and before the uniform aerated spot point has changes of the water surface profile.(2) In five different somatotypes of tests, in different unit discharge1#step horizontal surface essentially does not produce negative pressure, only in the large unit discharge vertical surface produce negative pressure, and the smaller of the absolute value of negative pressure. While2#step horizontal surface had negative pressure, in the small unit discharge vertical surface produce negative pressure, with increasing flow. rapid increase in the absolute value of negative pressure. The other steps are in the large unit discharge horizontal surface and vertical surface produce negative pressure.(3) Different somatotype in the same step height, the horizontal pressure:the four steps in fresh water flood district and the other steps in aeration non-uniform zone at in the large unit discharge produced negative pressure is not great. The vertical surface:with increase of unit discharge in fresh water flood district product absolute value of the negative pressure than the other steps in aeration non-uniform zone and gradually increased.(4) With the change in slope, the horizontal pressure and vertical pressure is not increase or decrease, but in0.4L or0.5H at the demarcation point.Through this study, revealed the root causes of the stepped spillway in the unit width discharge increase, in fresh water flood district of steps are easy to cavitation damage.