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绕经闸墩的水流,除自由表面和边墙受其影响外,其水流特性与二维障碍物影响水流特性相似。关于闸墩的水力特性研究已有大量资料可用来估算在容许范围内各种闸墩上的阻力。流线型闸墩可使阻力减小到一定值。本文的试验研究表明,在障碍物中开设纵向窄缝,通过纵缝的高速水流,由于在墩后产生尾波,引起更大的能量损失,从而使水流阻力减小。影响阻力系数主要有三个参数:佛如德数F_1、相对缝宽s/t和收缩比m(对于实体墩而言,C_D仅是F_1和m的函数)。水流的能量损失同样受这三个参数的影响。作者对这些参数对阻力系数和能量损失的影响进行了试验研究。
The water flow around the pier is similar to that of the two-dimensional obstacle except that the free surface and the side wall are affected by it. A great deal of information is available on the hydraulic characteristics of sluice piers to estimate the resistance of various sluice piers within the permissible range. Streamlined pier can reduce the resistance to a certain value. The experimental research in this paper shows that the opening of longitudinal slits in obstacles and the high-speed flow through the slits cause more energy loss due to coda waves generated at the pier, resulting in a decrease of water flow resistance. There are mainly three parameters that influence the drag coefficient: Fokude Number F_1, relative s s / t and shrink ratio m (for solid piers C_D is only a function of F_1 and m). The energy loss of the water flow is also affected by these three parameters. The authors have conducted experimental studies on the influence of these parameters on drag coefficient and energy loss.