High-precision format simulation method for one-dimensional ice-water coupling motion

Abstract

The invention relates to a high-precision format simulation method for one-dimensional ice-water coupling motion, and belongs to the field of river ice disaster forecasting. The method comprises the steps of boundary condition acquisition, equation control, ice-water coupling motion unified discretization, surface flux calculation, shallow water wave velocity calculation under the ice-water coupling condition and a high-precision format. According to the method, ice and hydrodynamic equations are uniformly dispersed into a high-precision Godunov format; an HLL approximate Rieman solution is adopted to calculate interface flux, equivalent water depth is adopted to replace section average water depth, piecewise linear reconstruction is carried out on basic variables of each unit in space, and a prediction-correction method is adopted in time, so that the precision of a numerical solution is integrally improved to a second order. The high-precision format simulation method for ice-water coupling movement has high prediction precision for the water level and ice thickness of the riverway in the flow ice period, particularly an equivalent water depth method is adopted to replace an average water depth method to calculate the wave velocity of shallow water waves, the water level prediction precision can be obviously improved, and research results are of great significance for prevention and control of ice disasters of the riverway.

Description

technical field [0001] The invention relates to the field of river ice disaster forecasting, in particular to river ice jams, ice dam occurrence locations and methods for forecasting ice jams and ice dam water levels. Background technique [0002] Ice conditions in rivers in severe cold regions of high latitudes in my country are severe, and ice dam ice flood disasters occur frequently. After the formation of ice dams in the river, the water level of the river rose rapidly, and even exceeded the highest flood level in history in each year, seriously threatening the lives and property safety of residents along the river. In addition, the momentum of drift ice is large, which can cause serious damage to hydraulic structures in the river or river-wading structures. In-depth study of the basic laws of river ice dynamic transport is of great significance to the prevention and control of ice dam ice flood disasters. [0003] During the closure and opening periods of the river, t...

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Problems solved by technology

There are several problems in this processing method: ① The four-point implicit finite difference method has first-order accuracy, and the simulation accuracy of complex flow conditions such as ice plug burst is poor; ② The artificial viscosity item lacks clear physical meaning, and the influence of human factors is relatively large. ③Shallow water wave velocity determines the flux at the hydrodynamic interface, and the motion characteristics of ice directly affect the shallow water wave velocity. There is a close coupling relationship between ice and water, and previous research results have ignored the impact of ice on shallow water wave velocity. Ice and water are considered to be loosely coupled

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