用Lattice Boltzmann方法计算流体对曲线边界的作用力

Evaluation of Fluid Acting Force on the Curve Boundary in the Lattice Boltzmann Method

通过分析格子Boltzmann方法中边界受力的计算方法,研究了两种用LB方法计算边界受力的方法———动量转换法和应力积分法,其中动量转换法较为可靠、准确,且易于执行.应用LB方法模拟了圆柱绕流问题,并计算出圆柱的阻力系数.通过模拟凹坑表面的层流流动,发现随着Re数的增大,凹坑表面的阻力系数逐渐接近平板的阻力系数.

Two approaches, the momentum-exchange method and the stress-integration method, for force evaluation based on the Lattice Boltzmann equation were investigated. The momentum-exchange method is relatively reliable, accurate, and easy to implement for both two-dimensional and three-dimensional flows. The flow around a cylinder was simulated, and the drag coefficient of the cylinder was evaluated by the momentum-exchange method. The drag coefficient of a concave surface was also evaluated and compared with the theoretical drag coefficient of a plane. The numerical results are valid, and the drag coefficient of the concave surface is close to that of the plan with the increase of Re number.