An Application Of BGK Boltzmann Theory To One-dimensional Dam-break Flow

The significance and history of dam-break flow calculations are reviewed in the thesis. It is pointed out that the traditional numerical models for open-channel flows are based on solutions of St. Venant equations, in which the basic assumption is that water flows must meet the continuity condition. However, the dam-break problem, strictly speaking, is of non-continuous wave problem. It has been proven that it is impossible to accurately and stably simulate dam-break wave by employing numerical models for open-channel flows based on St. Venant equations.The advantages of the BGK Boltzmann simulating method are summarized in the thesis. The possibility to simulate dam-break flows by employing this method is analyzed.Three steps are involved in the construction of the BGK numerical model for dam-break problems: (1) consistency analysis; (2) discrete step; (3) integrate step. The BGK numerical model of one-dimensional dam-break flows is formed by using Finite Volume Method and its executive program is induced.One-dimensional dam-break flows are simulated by the BGK numerical model and calculated results are compared with analytica solutions as well as those results obtained by other numerical methods. It shows that BGK numerical model is more precise, more stable and more efficient.This study shows that BGK numerical models based on BGK Boltzmann equation can simulate dam-break flows very well. As a new numerical method, it has a wide application area.