Numerical Analysis of Hydraulic Performance of negative surge on Earth Dam Discharge

1Farnaz Shasti, Elham Mina, Amir Khosrojerdi, Mohammad Reza Kavianpur

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Abstract:

The dynamic effects of the flood wave resulting from the failure of the dam have a high destructive power and a large volume of water accumulated in the reservoir in a short time suddenly empties and floods occur. The purpose of this research Performance of negative surge on Earth Dam Discharge. Simulation of gradual breakdown of the dam and expansion of the gap by modeling the software of HEC RAS software based on discontinuity of De St. Venant equations by numerical method of finite cross-sectional difference of four prism points and solving current flow equations due to gradual failure of the dam gradually There have been. Also, in the study of this phenomenon, the numerical method of the explicit boundary of McCormack's explicit differences has been used to break the St. Vincent equation. Examination of the dam's hydrographic failure of the dam in both case patterns indicates that in the case of dam failure in the hydrograph entry conditions into the reservoir, the volume of flood inflow into the reservoir moves like a wave on the negative wave in the reservoir and changes its shape. Due to the movement of the released current in the tank downwards, these changes gradually and over time spread to all areas of the tank and downstream, and increase the depth at all points in the tank, although the negative wave to the end The water level is not expected to decrease due to flooding at the reservoir at the beginning of the canal. However, the upward movement of the negative wave upwards can affect the expansion of the inflow flood flow in the reservoir and to some extent delay the discharge of the flood. Therefore, the results of comparing the flow hydrographic comparison of dam failure in HEC RAS model and explicit numerical model in dam failure mode and in the conditions of hydrographic entry into the reservoir indicate that the current prism model in HEC RAS model analysis has similar advantages and approximate results. McCormack is for solving the De St. Venant equations.

Keywords:

Explicit, supercritical, subcritical, Negative surges, Preissmann, peak breach discharge, De St. Venant.

Paper Details
Month8
Year2020
Volume24
IssueIssue 10
Pages4737-4751