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一、引言一般熟知的局部水力现象——水跃和跌水的研究,已有百余年的历史。但认真分析其所依据的边界条件(指边界几何要素,下同)后,便不难发现,所谓水跃和跌水,只不过是特殊边界条件下的局部水力现象而已。泄水建筑物出口轮廓与下游河床之间可能构成种种不同的边界条件,因此单纯研究任一特殊边界条件下的局部水力现象,缺乏普遍适用性。为此,本文初步探讨了一般边界条件下的局部水力现象;并将此现象定名为混合流,即射流与水跃流的混合流动。希望最终能为不同泄水建筑物下游的局部水力现象及相应的消能防冲问题,提供合理的解释途径和普遍可行的解决方法。
I. INTRODUCTION It is well-known that local hydraulic phenomena, such as the study of water jump and water drop, have a history of over one hundred years. However, after carefully analyzing the boundary conditions (referring to the geometric elements of the boundary, the same below), it is not hard to find out that the so-called water jump and water fall are only partial hydraulic phenomena under special boundary conditions. Therefore, the study of the local hydraulic phenomena under any special boundary condition lacks universal applicability because of the various boundary conditions that may be formed between the outlet profile of the discharge structure and the downstream riverbed. For this reason, the paper first explores the local hydraulic phenomena under the general boundary conditions. The phenomenon is named as mixed flow, that is, the mixed flow of jet and water jump. It is hoped that this will ultimately provide a reasonable explanation and a feasible solution to the local hydraulic phenomena downstream of different structures and the corresponding energy dissipation and erosion prevention issues.