泄槽底板与侧墙联合掺气保护长度试验

Experimental study on length of protective segment of combined bottom and side wall aerators on chute

为了研究近壁处水流掺气浓度分布的变化规律,通过模型试验研究了不同底坎坎比和不同侧坎坎比组合下掺气保护长度的变化规律,并通过单因素敏感性分析法分析了掺气保护长度对掺气坎坎比变化的敏感性。结果表明:在其他条件不变时,底掺气保护长度随着流量的增大而增大,同时与底坎坎比成正比;随着侧坎坎比增大,底掺气保护长度略有增大的趋势,但影响不大;侧掺气保护长度也随着流量增大而增大,但与底掺气保护长度的机理不尽相同;随着侧坎坎比的增大,侧掺气保护长度总体趋势增大,但影响程度表现为先大后小;虽然侧掺气保护长度对侧坎坎比的敏感性远大于底掺气长度对底坎坎比的敏感性,但底坎坎比却更为重要;合理的掺气设施组合才能有效地提高掺气保护范围。

In order to study the air concentration distribution in the flow area near the solid bottom and walls of a chute, the length of a protective segment in response to a combination of bottom and lateral aerators with different height-to-length ratios was investigated through model experiments, and the sensitivity of the length of the protective segment of the aeration facility to the height-to-length ratio of the aerator was analyzed using the single-parameter sensitivity analysis method. The results show that, when the conditions of other factors remain unchanged, the length of the protective segment of the bottom aerator increases with the discharge and the height-to-length ratio of the bottom aerator, and increases slightly with the height-to-length ratio of the lateral aerator. The length of the protective segment of the lateral aerator increases with the discharge and, with the increase of the height-to-length ratio of the lateral aerator, it increases quickly at first and then slowly. Although the sensitivity of the length of the protective segment of the lateral aerator to the height-to-length ratio of the lateral aerator is higher than the sensitivity of the length of the protective segment of the bottom aerator to the height-to-length ratio of the bottom length, the height-to-length ratio of the bottom aerator is more important to the whole length of the protective segment of the aeration facility. The length of the protective segment can be effectively increased only when a reasonable combination of aeration facilities is used.