Calculation And Analysis For Torrent Shock Wave

In practical projects, because of the limitations of the terrain or the requirements of projects, some sects of pervasion, constriction or bending river course are arranged with such flood-discharge tunnels as spillway or chute. Under this situation, the flow, when it is the torrent through the channel, will be disturbed due to the variations of the trough wall deflection;therefore, at the downstream will appear a series of rhombic disturbed waves called torrent shock waves. Torrent shock waves can be divided into steep shock wave and flat shock wave. When riverside turns to the inner of current, it causes steep shock wave. When riverside turns to the exterior of current, it causes flat shock wave.In this paper analysis and calculation were discussed for these two type shock waves separately. According to Von Karman' s formula of integration of flat shock wave ,an deflection angle condition for shock wave attaching was obtained. Based on differential expression of flat shock wave and Runge-Kutta method, a numerical algorithm was established. The method has the merits of convenient computation and easy programming.For steep shock wave, its reflection case was analyzed. The essential condition of reflection stopping was put forward based on the attachment condition of steep shock waves. According to Ippen's shock wave theory and the computational methods of steep shock waves, the maximal length of the deflection wall was analyzed.At the last part of this paper, the computational method for the length of the contractions was achieved.The result of studies in this paper shall be the basis for studying the torrent shock wave with more complexity structure.