摘要
用基于特征线的算子分裂(CBOS)有限元法求解Naiver-Stokes方程:即在每一个时间层上,采用算子分裂法将N-S方程的对流项与扩散项分开求解,对流项离散采用特征线-Galerkin法,显式求解。流体自由表面跟踪采用浓度法,建立了新的水波模型。经过下游河床有水、无水溃坝模型的验证,表明该模型能精确模拟带自由表面流体运动问题。同时,研究了下游河床无水时溃坝模型自由水面运动特征;探讨了下游河床有水时溃坝模型中涌浪波形成原因、波浪翻卷形成过程,并分析了涌浪波与下游河床水体冲击接触瞬间,下游河床压力突然增大这一现象。
A new finite element method, which is the characteristic-based operator-splitting （CBOS） algorithm, is adopted to solve Navier-Stokes （N-S） equations. In each time step, the equations are split into a diffusive part and a convective part. The convective part is discretized using the characteristic Galerkin method and solved explicitly. The moving interface is captured by the pseudo-concentration method, thus, a new wave model is established. Through the validation of dam break failure onto a downstream dry bed or a wet bed, it is shown that the present model can accurately simulate the generation and the transmission of the dam breaking flow. We also study the evolution characteristics of the free surface in the dry bed case. Meanwhile, the generation of surge waves and the formation of curling waves are discussed for the wet bed case. In addition, it is analyzed that the pressure of the downstream bed suddenly increases under the impact of the surge waves on the water body of the downstream wet bed.
出处
《工程力学》
EI
CSCD
北大核心
2013年第3期451-458,共8页
Engineering Mechanics
基金
国家自然科学基金项目(41072235
50809008
41110104031)
香港研究资助局基金项目(HKU7171/06E)
辽宁省自然科学基金项目(20102006)
关键词
流体力学
溃坝
CBOS有限元
浓度法
水波模型
fluid mechanics
dam breaking
CBOS finite element method
Pseudo-concentration method
wavemodel
