梯度润湿表面上液滴定向迁移及合并行为的格子Boltzmann模拟

采用改进的格子Boltzmann方法，对梯度润湿性表面上液滴的定向迁移及合并行为进行了数值模拟，该模型在精度和稳定性上都有很大改善，同时，研究了梯度润湿性表面上液滴定向迁移和合并的动力学特性，并对液滴尺寸及润湿梯度对液滴动力学特性的影响规律进行了分析。数值结果表明，液滴在梯度润湿性表面运动时会发生形变，且动态接触角逐渐减小。润湿梯度对液滴定向迁移行为有显著影响，润湿梯度越大，液滴左右侧接触线位移越大，润湿长度增加越快。但是液滴尺寸对接触线位移影响较小。润湿梯度对液桥宽度基本无影响，但对液滴初始合并时间有显著影响。

Simulation of droplet directional migration and coalescence on gradient wetting surfaces by lattice Boltzmann method

Directional migration and coalescence of droplets on gradient wetting surfaces were simulated by improved lattice Boltzmann method.The accuracy and stability of this model can be greatly improved.And evolutional characteristics of droplet directional migration and coalescence on gradient wetting surfaces were studied.Besides,the effect of droplet size and wetting gradient on the dynamic behavior was analyzed.The numerical results indicated that droplet deformation can be seen and dynamic contact angle decreases when moving on gradient wetting surfaces.Wetting gradient has a great effect on the droplet directional motion.Displacement of the left and right contact line and wetting length increase with the increase in wetting gradient.However,droplet size has little influence on displacement of contact line.The wetting gradient has no effect on the width of the liquid bridge,but it has a significant impact on the initial coalescence time of the droplets.