板壁水膜波动流动数值研究

板壁水膜流动特性是影响水膜二次携带的主要因素之一.通过数值方法对某一规格板壁表面水膜波动流动特性进行研究.在对水膜表面进行受力分析的基础上,得出了水膜自由表面的动力学边界条件,建立了板壁水膜波动流动的数学模型.连续性方程采用中心差分格式,动量方程采用迎风和中心差分混合的偏心差分格式,采用Simple算法对板壁水膜波动流动方程进行了求解,采用流体界面追踪法(VOF:Volume-of-Fluid)方法对水膜自由表面进行模拟追踪.计算结果表明,水膜在板壁中部的波动比其它部位剧烈,另外也发现入口扰动频率对水膜波动的影响程度要大于扰动振幅对水膜波动的影响.

Numerical Study of Water Film Wave Flowing on Wall

The flowing characteristic of water film on wall is one of the main factors that influences the secondary droplets entrainment. This paper studies the flowing characteristic of water film on wall of certain sizes, using numerical method. Based on the analysis of water film surface forces, the dynamic boundary condition of water film free surface was obtained, and the wave flow models of water film on wall were established. The central-differencing algorithm was used for the continuity equation. And the blend of two-order upwind difference algorithm and central-differencing algorithm was used for the Momentum equation. SIMPLE and VOF algorithm were used to solver the wave flow of water film on wall. Calculation results showed that the water file waved more acutely in the middle of wall than other places, and the inlet interferential frequency influenced the wave flow of water film more intensively than the inlet interferential.