 Study on takeoff angle characteristics of continuous flip bucket's ski-jump nappe

DOI：10.13244/j.cnki.jiwhr.20220102

 作者 单位 E-mail 隆强 四川大学 水利水电学院, 四川 成都 610065 刘超 四川大学 水利水电学院, 四川 成都 610065 liuchao@scu.edu.cn 邓军 四川大学 水利水电学院, 四川 成都 610065 卫望汝 四川大学 水利水电学院, 四川 成都 610065 冉雨博 四川大学 水利水电学院, 四川 成都 610065

本研究采用基于VOF水气两相流的标准k-ε双方程紊流数学模型对连续坎挑流水舌出射角特性进行了三维数值模拟研究,为计算挑流水舌出射角与挑坎体型角的差值提供理论支撑,从而达到修正工程中挑流水舌实际出射角的目的。基于不同来流条件、挑坎体型尺寸下的系列计算数据分析了来流水深、坎前断面流速、反弧半径以及挑坎挑角对挑流水舌底缘出射角、上缘出射角和出射角断面分布的影响,获得了出射角的变化规律。研究结果表明,挑流水舌出射角沿水深方向逐渐减小,底缘出射角大于上缘出射角但两者均小于挑坎挑角,并揭示了来流弗劳德数、挑坎体型参数对底缘出射角差以及断面平均出射角差的影响规律且建立了相应的计算方法,可为连续坎挑流水舌计算水舌挑距、入水范围提供精确的出射角,有助于挑流消能设计水平的提升。

In this study,three-dimensional numerical simulation of the takeoff angle characteristics of continuous flip bucket’s ski-jump nappe is carried out by using the standard k-ε equation turbulence model based on VOF water-gas two-phase flow.The study would be able to provide theoretical support for calculating the difference between the takeoff angle of ski-jump nappe and the flip bucket angle,so as to correct the actual takeoff angle of ski-jump nappe in the project.Based on a series of calculation data with different approach flow conditions and geometric parameters of the flip bucket,the influence of the approach flow depth,the approach flow velocity,the flip bucket curvature and the flip bucket angle on the bottom and upper takeoff angle of ski-jump nappe,and the section distribution of takeoff angle are analyzed.The variation law of the takeoff angle is obtained.The results show that the takeoff angle of ski-jump nappe decreases gradually along the flow depth direction and the takeoff angle of the bottom angle is larger than the upper angle but both are smaller than the flip bucket angle.In this paper,the influence laws of the approach Froude number and the geometric parameters of flip bucket on the bottom takeoff angle difference and section average takeoff angle difference are revealed and corresponding calculation method is established.This method can provide an accurate takeoff angle for calculating ski-jump nappe trajectory length and the range of nappe plunging into the pool of continuous flip buckets and help to improve the design level of ski-jump energy dissipation.