明流泄水道突扩突跌掺气设施空腔长度研究

为了查明短有压进口泄洪洞下游明流泄水道上突扩突跌掺气设施底、侧空腔长度随掺气坎尺寸和水流弗劳德数的变化规律,采用模型试验,测试了不同掺气坎尺寸在不同水流条件下的底、侧空腔长度,分析了无量纲底、侧空腔长度与掺气坎尺寸和水流弗劳德数的相互关系.结果表明:底空腔长度随着挑坎高度的增加、挑坎坡度的增大、侧扩宽度的增加和水流弗劳德数的增大而增大;侧空腔长度与挑坎高度、挑坎坡度关系不大,随着侧扩宽度的增加而增大,随水流弗劳德数的变化规律为:当侧扩宽度较大时,侧空腔长度随水流弗劳德数的增大而线性增大;当侧扩宽度较小时,侧空腔长度随水流弗劳德数的增大而略微减小.

Research on Cavity Length of Aerator with Sudden Lateral Enlargement and Vertical Drop in Free Flow Chute

For an aerator with sudden lateral enlargement and vertical drop in free flow chute, the cavity length is governed by a number of independent parameters, including the Froude number, the ramp height of vertical drop, the ramp angle of vertical drop, the lateral enlargement width of sidewalls, etc. Based on model experiments, the effects of above-mentioned parameters were observed on the bottom cavity length and the lateral cavity length. The results show that the bottom cavity length is closely related to the ramp height, the ramp angle, the lateral enlargement width and the Froude number, and with higher ramp height, bigger ramp angle, wider lateral enlargement width, and higher Froude number, the bottom cavity length is longer. Yet the lateral cavity length is mainly connected with the lateral enlargement width and the Froude number, which has little relation to the ramp height and the ramp angle. For the lateral cavity length, it increases with the lateral enlargement width. At the condition of larger size of lateral enlargement, the lateral cavity length increases linearly with the Froude number, while a little decreases when the size of lateral enlargement is smaller.