与宽尾墩联合使用的台阶面水流掺气问题研究

通过工程试验资料与原型资料的分析类比发现，与宽尾墩联合使用的台阶面近底水流，满足掺气减蚀进气量需要的空腔，必须是台阶初始段有6～8个台阶脱空的空腔，而形成这一空腔的堰面末端掺气坎高度既与坎型有关，也与宽尾墩型式有关。台阶高度对台阶面大单宽过流掺气浓度沿程变化影响很小，掺气浓度随台阶面坡比的变化比较明显，坡度越缓，沿程衰减越明显，同时掺气浓度随堰上水头增加而增大，堰面使用Y型宽尾墩掺气量最大，无墩时最小，使用X墩时，处于二者之间。与宽尾墩联合使用的台阶面大单宽过流掺气量可以满足减蚀需要，而无墩时掺气量不能满足需要。

The Study on Skimming Flow Aeration on the Combination of Stepped & Flaring Gate Piers

Based on the information of experiments & full scale test, the paper analyses the aeration on skimming flow close to its bottom with the combination of stepped & flaring gate piers. As a result, the air cavity length is 6-8 step without water, the aerated bucket has relation to bucket type& flaring gate piers. Air concentration vary with step chute slope and the head of crest, flaring gate piers. Step height influence can be considered negligible. Air concentration is more large which flow on steep slope and the Y type flaring gate piers. It has been proved by engineering prototype that large discharge skimming flow aeration protects against cavitation damage with the combination of stepped & flaring gate piers.