摘要
利用流体仿真软件FLUENT对高水头明流泄洪洞不同体型反弧段的水流流场进行三维数值模拟,获取了流速、压强、切应力等水流运动参数的沿程分布。结果表明:不同形式的反弧段,沿程水头损失差别很小;反弧段的曲率半径越小,底板压强越大,同时在反弧段始、末断面附近的压强梯度也大;各种类型的反弧段底板剪应力基本呈沿程增大的趋势,但前半部和后半部底板切应力的变化规律不同。综合考虑反弧段流速、底板压强、底板切应力的沿程分布情况,采用下过渡曲线形式的反弧段体型可以减小反弧段与下斜坡段连接部位的压强梯度和切应力,相对于文中提到的其他体型的反弧段,空蚀风险最小。
The commercial fluid simulation software FLUENT is employed to investigate the effect of the concave types on the 3D flow hydraulic characteristics in a spillway tunnel with high speed flow.The distribution laws of velocity,pressure and the shear stress characteristic of water flow are obtained.The results show that the difference of frictional head loss of water is very little in the spillway tunnel with different concave segments,the bottom pressure and the pressure gradient at the initial and final sections of the concave flow increase as the invert curvature radius decreases.The bottom shear stress increases along the invert with different concave segments.But the change law on the upstream and downstream concaves is different.The pressure gradient and the bottom shear stress at the joint between the concave segment and downstream slope will decrease by applying the concave segment with down transition curve type.The results indicate that it can reduce cavitation erosion risk to high velocity spillway tunnels as the concave segment with down transition curve type is adopted.
出处
《中国农村水利水电》
北大核心
2012年第4期133-138,共6页
China Rural Water and Hydropower
基金
国家自然科学基金项目(51109150
50978173
50909067
51179114)
关键词
泄洪洞
不同曲率反弧段
水力特性
数值模拟
spillway tunnel
the concave segment with different curvature radius
hydraulic characteristics
numerical simulation
