缩放式洞内消能工水动力学特性数值研究

Study on hydraulic characteristics of contraction-expansion energy dissipater based on numerical simulation

缩放式消能工有着消能效率高、构造方便的特点,在我国水电事业中有着广泛的应用前景,因此有必要研究缩放式消能工的水力学特性。本文主要通过数值模拟的途径,研究了缩放式消能工的水力学特性与相关体型要素的关系,并且重点比较了孔板与洞塞这两类消能工的共性与差异。研究结果表明,在厚度不变的情况下,孔板与洞塞这两种缩放式消能工的能量损失系数均随着孔径比的增加而变小;在孔径比不变的情况下,孔板的能量损失系数随厚度的增加而减小,洞塞的能量损失系数几乎不受其厚度的影响;在相同孔径比和入口水流条件下,孔板的消能效果要优于洞塞。

Energy dissipater with abruptly-contracted and expanded cross sections, featured with high energy dissipation efficiency and convenient construction, has a broad application prospect in China. It is significant to explore and understand its hydraulic characteristics. This paper presents a study on the relationships of energy loss coefficient versus geometry parameters for this type of energy dissipaters, focusing on a comparison of flows in the orifice plate and tunnel plug dissipaters. Results indicate that the energy dissipation coefficients of plug and orifice both decrease with contraction ratio and that under a fixed contraction ratio, the energy loss coefficient of orifice plate decrease with its thickness while that of plug varies little. Under a fixed contraction ratio, the energy dissipation efficiency of orifice plate is higher than that of plug dissipater.