波浪爬高是海岸工程中常见的水力学问题之一,其数值模拟方法通常是离散Navier-Stokes方程或Bouss inesq方程。与之不同,近几年发展起来的Lattice Boltzmann方法(LBM)是采用具有特定演化规则的粒子系统模拟流体运动。此方法具有计算效率高及内在并行等优点。本文将LBM应用于陡墙上孤立波的爬高模拟,建立了不可压缩流体的LB模型,并把VOF的概念引入到LBM中模拟自由表面的运动。分析和实践表明,本文方法适用于自由表面无破碎的不可压缩流体的数值模拟;对于表面破碎的情况,应将LBM与紊流模型结合,并且液面运动的模拟须采用气液两相流界面的计算方法。
The Lattice Boltzmann method(LBM), in which the flows are simulated by using a particle system with particular evolution rules is applied to simulate the run-up of solitary waves on a steep slope. This method is efficient and intrinsically parallel. A LB model for incompressible flows was established, and the VOF concept was introduced into the model to simulate the action of free surface. Both theoretical analysis and the simulation result show that the model in the paper is applicable to simulate the incompressible flows with a free surface without breaking. For simulating a broken water surface, LBM should be combined with the turbulence models and the free surface should be turned into the interface in gas-liquid flows.