渐缩突扩式洞塞水力特性的数值模拟研究

Numerical Simulation of Hydraulic Characteristics of Tapered Contraction-sudden Expansion Plug

为了深入了解新型渐缩突扩式洞塞泄洪洞的压强分布和消能率等水力特性,采用三维RNGκ-ε紊流数学模型对渐缩突扩洞塞段水流进行了数值模拟研究,分析了雷诺数、收缩比和相对长度对渐缩突扩洞塞的局部水头损失系数和最小压强系数的影响,并与顺直洞塞的对应水力参数进行对比。结果表明,渐缩突扩洞塞的局部水头损失系数和最小压强系数主要受收缩比和相对长度的影响,且收缩比的影响比相对长度显著。随着收缩比和相对长度的增大,局部水头损失系数和最小压强系数相应减小。与顺直洞塞相比,渐缩突扩洞塞的消能率较小,但具有更强的抵抗空蚀破坏的能力。

In order to understand the hydraulic characteristics such as pressure distribution and energy dissipation rate of a new type of the tapered contraction-sudden expansion plug,a three-dimensional RNGκ-εturbulence mathematical model is used to simulate the tapered contraction-sudden expansion plug.The impacts of Reynolds number,contraction ratio and relative length on the local head loss coefficient and minimum wall pressure coefficient of tapered contractionsudden expansion plug are analyzed,and compared with the corresponding hydraulic parameters of the linear plug.The results show that the local head loss coefficient and the minimum wall pressure coefficient are mainly affected by the contraction ratio and relative length,and the impact of contraction ratio is more significant than that of relative length.With the increase of contraction ratio and relative length,the local head loss coefficient and the minimum wall pressure coefficient decrease correspondingly.Compared with the linear plug,the energy dissipation rate of the tapered contraction-sudden expansion plug is smaller,but it has stronger ability to resist cavitation damage.