scholarly journals 2D NUMERICAL SIMULATION OF TIDAL BORE ON QIANTANG RIVER USING KFVS SCHEME

2011 ◽  
Vol 1 (32) ◽  
pp. 29 ◽  
Author(s):  
Cun-Hong Pan ◽  
Haiyan Lu
Keyword(s):  
Moving Boundary ◽  
Triangular Grid ◽  
Order Accuracy ◽  
Tidal Bore ◽  
Qiantang River ◽  
Whole Process ◽  
Boundary Treatment ◽  
Maximal Height ◽  
Flux Vector Splitting ◽  
Volume Method

Qiantang estuary is famous worldwide for tidal bore, whose maximal height reaches about 4 m. In this paper, a new numerical model, based on Boltzmann equation, Kinetic Flux Vector Splitting (KFVS) scheme with the finite-volume method combined with the improved Riemann solution for moving boundary treatment, is constructed to numerically simulate the tidal bore on the Qiantang River. The model is discretized by unstructured triangular grid and has the second order accuracy in spaces. The simulated results show that the model can simulate the whole process of formation, evolution, and dissipation of the tidal bore on the Qiantang River. The typical bore sceneries such as the crossed bore, the thread-shape bore and the returned tidal bore have been reproduced. These studies lead to more understanding about the characteristics of the tidal bore.

An Accurate Unstructured Finite Volume Discrete Boltzmann Method

2018 ◽  
Author(s):  
Leitao Chen ◽  
Laura Schaefer ◽  
Xiaofeng Cai
Keyword(s):  
Finite Volume ◽  
Lattice Boltzmann ◽  
Unstructured Grid ◽  
Interpolation Scheme ◽  
Time Space ◽  
Boundary Treatment ◽  
Complex Boundary ◽  
Volume Method ◽  
Boltzmann Method ◽  
Boltzmann Model

Unlike the conventional lattice Boltzmann method (LBM), the discrete Boltzmann method (DBM) is Eulerian in nature and decouples the discretization of particle velocity space from configuration space and time space, which allows the use of an unstructured grid to exactly capture complex boundary geometries. A discrete Boltzmann model that solves the discrete Boltzmann equation (DBE) with the finite volume method (FVM) on a triangular unstructured grid is developed. The accuracy of the model is improved with the proposed high-order flux schemes and interpolation scheme. The boundary treatment for commonly used boundary conditions is also formulated. A series of problems with both periodic and non-periodic boundaries are simulated. The results show that the new model can significantly reduce numerical viscosity.

Numerical Simulation of Flash Floods Routing Based on Improved Leap-Frog Method

2013 ◽  
Vol 347-350 ◽  
pp. 2173-2177
Author(s):  
Jia Hua Zhang ◽  
Chi Zhang
Keyword(s):  
Numerical Simulation ◽  
Moving Boundary ◽  
Simulation Analysis ◽  
Flash Flood ◽  
Mass Conservation ◽  
Correction Method ◽  
Gansu Province ◽  
Simulation Accuracy ◽  
Whole Process ◽  
Steep Terrain

in the 2-d numerical simulation of flash flood disaster, due to flood often occurred in the steep terrain and water flow rapidly changed, lead to that the calculated value is unstable and even the calculation diverge in the simulation. This paper presents a grid outflow correction method, which is based on the leap-frog finite difference format, through modifying the outflow rate of the grid circularly, to ensure the mass conservation in the whole process of computing. In the local dam bursting model, the simulated result comparison of the grid outflow correction method and the algorithm of implicit alternating direction on the mass conservation shows that, the new method can ensure the simulation accuracy and the numerical stability under the condition of steep terrain and moving boundary. According to the proposed method, the simulation analysis in the process of extreme flash flood disasters which happened in 2010 Zhouqu county in Gansu province was carried out. The comparison of simulation results and remote sensing estimation results shows that the deviation of the flood evolution time, speed and impact height are within 5%, and the consistency of evolution path is good, which verifies the validity of the algorithm.

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