ABSTRACT

The work focuses on developing a detailed understanding of the effects of initial composition (C_in) and bottom cooling temperatures (T_B) on different characteristics of double-diffusive convection during unidirectional solidification of water-NH₄Cl solution in a complete non-intrusive manner. The qualitative investigation, simultaneous quantification of transported parameters (composition and temperature) and fluid velocities associated with flow patterns are carried out using rainbow schlieren deflectometry, dual-wavelength interferometry and PIV (particle image velocimetry) technique respectively. The dependence of the characteristics of double-diffusive convection for different C_in and T_B is explained on the basis of real-time whole-field investigation using a combination of aforementioned imaging techniques.

摘要

这项工作的重点是详细了解初始成分 (C _in ) 和底部冷却温度 ( T _{B ) 对水-NH 4} Cl 溶液在完全非侵入式单向凝固过程中双扩散对流的不同特性的影响方式。分别使用彩虹纹影偏转仪、双波长干涉仪和 PIV（粒子图像测速仪）技术对与流动模式相关的传输参数（成分和温度）和流体速度进行定性研究、同步量化。双扩散对流特性对不同C _in和T的依赖性_B是在使用上述成像技术的组合进行实时全场调查的基础上进行解释的。