抄録
This paper describes the basic characteristics of the development of supercritical flows in the downstream of an abrupt expansion in a steep open channel. Although Rouse and Bhoot (1951) showed the method of analysis to calculate supercritical flows in the downstream of an abrupt expansion based on Method of Characteristics (MOC) with a graphical method, and the authors developed MOC based computational method using the fixed grid system, the basic characteristics of flow development have not been clarified. In this paper, it is shown that the flow characteristics can be classified into two regions. One flow region called the pressure-inertia region is located in just downstream of an expansion and the flow characteristics can be reproduced by the approximate solution based on MOC to the shallow flow equations. The other flow region extends in the downstream of an expansion, and the flow developments can be formulated by applying the self-similarity distribution analysis.
