【摘要】 本文采用格子Boltzmann方法和高速显微摄像装置对液液系统中的液滴合并过程进行了数值模拟和可视化实验观测,研究了液滴形貌变化及其液滴合并动力学行为,并重点分析了液滴合并过程中液桥半径随时间的变化。研究结果表明:当两液滴接触开始合并,液桥半径迅速增加至一极值,随后出现振荡波动直至稳定。在液滴合并初始阶段,存在由黏性主导向惯性主导转变的过渡区域。当液滴合并转为惯性主导阶段时,桥半径与时间的开方之间线性相关,实验与模拟得到的桥半径曲线前因数分别为0.92与1.023,两者基本一致,验证了本文所建立液滴合并数学模型正确可靠。更多还原

【Abstract】 The coalescence of two resting liquid droplets immersed in another liquid is numerically investigated by lattice Boltzmann method and experimentally observed with the high-speed microscopic imaging system.The morphology evolution and the dynamic behavior of droplet coalescence are analyzed with a focus on the variation of liquid bridge radius with time.The results indicate that as two droplets contact,the liquid bridge radius monotonically increases at first and then starts to fluctuate until a stable process is reached.In the initial coalescence period,there exists a transition from viscous effects domination to inertia effects domination where the liquid bridge radius increases linearly with the square root of time.The obtained prefactors of this power-law relationship by using numerical and experimental methods are 1.023 and 0.92 respectively,which validates the droplet coalescence model in this paper.更多还原