明渠渐变段体型对渐变段中的水流形态有很大影响。为了解决明渠渐变段与下游水流的扩散衔接问题,消除明渠渐变段下游菱形冲击波的影响,根据冲击波特性和辐射水流基本关系,采用冲击波简化积分式,并考虑到渐变段水流与下游衔接,按刘韩生曲线边墙窄缝挑坎计算方法算出明渠曲线渐变段边墙体型,且该方法能够计算渐变段中的水面线。试验表明明渠曲线渐变段中水流平顺稳定且水面渐变升高。渐变段后水流正常,为均匀流,无菱形冲击波的影响,故能够解决水流扩散衔接的问题,该方法可以运用到明渠曲线渐变段边墙体型设计中。

The shape of transition section has great influence on the flow pattern in open channel. The aim of this research is to address the problem of flow diffusion and the coherence between transition section and downstream flow, and to eliminate the impact of diamond-shaped shock wave in the downstream of open channel. According to the characteristics of shock wave and the basic relationship between shock wave and radical flow, we calculated the shape of the transition section with curved side-wall in open channel by adopting the simplified integral equation of shock wave following Liu Hansheng's formula of slit-bucket with curved side-wall. The flow coherence between the transition section and the downstream was also considered. This method can calculate the water surface curve in the transition section. Test results show that the flow in the transition section of open channel is smooth and stable, and water surface rises gradually. After the transition section, the water flow is normal, which is uniform flow, with no impact of diamond-shaped shock wave, demonstrating that this method could solve the problem of flow diffusion and coherence, hence can be applied to the design of transition section with curved side-wall.