高水头弧形闸门出口侧墙空化特性及掺气减蚀研究  

Cavitation Characteristics and Aeration Mitigation for the Sidewall of a Radial Gate in a High-head Tunnel

作　　者：王伟[1] 邓军[2] 卫望汝[2] WANG Wei;DENG Jun;WEI Wangru(Sichuan Water Conservancy Vocational College,Chengdu 611830,China;State Key Laborary of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川水利职业技术学院,四川成都611830 [2]四川大学山区河流保护与治理全国重点实验室,四川成都610065

出　　处：《工程科学与技术》2025年第2期84-92,共9页Advanced Engineering Sciences

基　　金：国家自然科学基金项目(51939007,U23A20668,51979182,51979183)。

摘　　要：高水头泄洪放空洞弧形闸门出口往往需要设置掺气设施以减免高速水流空化空蚀破坏。由于有压出口区域水流流态与结构壁面相互作用复杂,易导致掺气减蚀保护失效,目前,其核心水力致灾原因尚不明确,并且制约着适用于弧形闸门掺气减蚀的技术研发。本文结合实际工程中高水头弧形闸门出口侧墙空蚀破坏实例,采用水力学模型试验与数值模拟方法,对空蚀破坏的水力学成因进行系统分析,并提出了掺气减蚀水力设计方案。结果表明,弧形闸门泄流运行时,高速水流横向扩散显著,侧空腔掺气效果较差,在侧向附壁过程中形成侧墙冲击-低压反射区,导致附壁区水流空化数较低,并存在侧墙清水区域,二者共同作用导致泄洪放空洞侧墙发生空化空蚀破坏,这种不利影响在大流量、闸门局开条件下更为严重。基于提高侧墙水流空化数与改善侧掺气空腔掺气效果,提出了侧墙二级收缩掺气坎,实现低压空蚀风险区域水流脱壁,末端侧向水流附壁全断面掺气减蚀。研究成果将为弧形闸门出口掺气减蚀水力设计提供科学依据,保障高水头泄洪建筑物的安全运行。Objective In high-head spillway tunnels,aeration devices are often installed at the outset of the radial gate to reduce cavitation erosion.Despite these precautions,cavitation erosion persists due to the complex flow pattern near the radial gate.Once the flow is discharged into an open channel,the pressure relief effect lead to the diffusion of high-speed flow and the flow quickly reaches the bottom and side walls of the channel,resulting clogging risk in aeration area.Up to the present,the hydraulic reason for weakening the aeration performance are still unknown,and there are little hydraulic designs to improve the aeration protection for the radial gate.Typically,the lateral and bottom aerators are installed at the pressurized outlet when the flow is directed into an open channel under high-head conditions.However,the lateral and vertical diffusions of flow complicates the flow pattern near the radial gate,influencing the effectiveness of the lateral and bottom aerators.It is significant to understand the aeration protection nullification mechanism and propose effective aerator designs for the sidewall and bottom protection.The present study focused on a given prototype hydraulic engineering featuring a radial gate in a high-head spillway tunnel,where the tunnel wall is damaged by cavitation erosion.Methods Focused on the cavitation erosion in the given prototype tunnel,the present study obtained the hydraulic characteristics based on experimental and numerical results,optimizing the lateral aerator.The physical model was designed based on Froude similarity criterion,and the numerical simulation model was established according to the prototype tunnel.The effects of aeration devices on the aeration protection efficiency were analyzed using aeration flow pattern,cavity length,flow velocity field and flow cavitation number.In the present study,the RNG k-εturbulent model was used to simulate three-dimensional flow field of the radial gate,the VOF was used to simulate the aeration cavity,and the partial differentia

关 键 词：高速水流 弧形闸门 空蚀破坏 掺气减蚀 泄洪洞 

分 类 号：TV131.3[水利工程—水力学及河流动力学]