前置掺气坎式阶梯溢洪道体型布置优化试验研究
Experimental Investigation on Hydraulic Characteristics of the Flow in the Pre-aerator Stepped Spillways
作者：吴守荣(四川大学 水力学与山区河流开发保护国家重点实验室，四川 成都 610065)；张建民(四川大学 水力学与山区河流开发保护国家重点实验室，四川 成都 610065)；许唯临(四川大学 水力学与山区河流开发保护国家重点实验室，四川 成都 610065)
Author：(State Key Lab. of Hydraulic and Mountain River Eng., Sichuan Univ., Chengdu 610065, China)；(State Key Lab. of Hydraulic and Mountain River Eng., Sichuan Univ., Chengdu 610065, China)；(State Key Lab. of Hydraulic and Mountain River Eng., Sichuan Univ., Chengdu 610065, China)
收稿日期：2007-04-25 年卷（期）页码：2008,40(3):37-42
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：阶梯式溢洪道；前置掺气坎；水力特性；试验研究；掺气减蚀
Key words：stepped spillway; pre-aerator；hydraulic characteristics;experimental investigation;air entrainment and cavitation erosion
基金项目：国家杰出青年科学基金资助项目（50325928）;国家自然科学基金委员会、二滩水电开发有限责任公司、雅砻江水电开发联合研究基金资助项目（50539060）;国家自然科学基金资助项目（50479062）联合资助项目
中文摘要
对光滑溢洪道、阶梯溢洪道和前置掺气坎式阶梯溢洪道水力特性进行了对比研究。针对阶梯式溢洪道工作水头很高，单宽流量超过50 m3/s的工程中尚没有成功应用实例的难题，提出采用前置掺气坎式阶梯溢洪道即能保持阶梯溢洪道的较大消能率，又能通过控制掺气浓度保护台阶表面避免发生空蚀破坏，较好的解决了溢洪道体型优化和下游消能防冲问题。对前置掺气坎式阶梯溢洪道水力特性、消能特性、掺气效果、抗空蚀特性进行分析和研究，成果表明，通过掺气坎和台阶的体型优化，各级流量的消能率均达到70％左右，尽管台阶后负压达-2.3 kPa量级，实测溢洪道台阶竖直面后的掺气浓度沿程分布均大于5%，与传统阶梯式溢洪道相比，抗空蚀性能明显提高，与光滑溢洪道相比，消能率提高2～4倍，消能效果良好。
英文摘要
The hydraulic characteristics of the smooth spillway, the stepped spillway and the pre aerator stepped spillway have been studied respectively. By now the stepped spillway hasn't been applied successfully in instance project when the water head is very high and the unit discharge exceed to 50 m3/s.To overcome this problem,the pre-aerator is advanced which can not only keep the stepped spillway’s large energy dissipation ratio, but also protect the step from cavitation damage by controlling the aeration concentration of flow.Energy dissipation and erosion problems can be both solved by using the pre-aerator in a stepped spillway. The hydraulic characteristics induding energy dissipation and aeration effectiveness and anti-cavitation erosion are deeply analysed and studied. The achievements indicate that after optimizing the configuration of the aeration the step the energy dissipation ratio can reach to 70%.Although the pressure on the wall back the step can reach to -2.3 kPa, the measurement of the aeration concentration is bigger than 5% at the spillway step’s vertical surface. Compare to the stepped spillway, the pre-aerator stepped spillway has a better characteristics against the cavitation erosion and the energy dissipation ratio is 2~4 times higher than the smooth spillway.
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