Hydrodynamics of free-falling turbulent wavy films and implications for enhanced heat transfer

作者：Ye Xuemin; Yan Weiping^*; Jiang Zhangyan; Li Chunxi

来源：Heat Transfer Engineering, 2002, 23(1): 48-60.

DOI：10.1080/014576302753249606

• Conductance sensors
• Coordinate transformation
• Free falling turbulent wavy films

The evolution of the surface waves for vertical free-falling films with Reynolds number ranging from 440 to 5,100 was measured using multiple-point conductance sensors and a computer-based data acquisition system. The physical and mathematical models describing the free-falling turbulent wavy films with the free surface boundary are presented. The governing equations are solved numerically in the film waves based on the coordinate transformation of the measured time-dependent film thickness data. The results show that the evolution of the surface waves has a remarkably nonlinear nature. The hydrodynamics and velocity profiles at the wave front, the wave crest, and the wave back for the solitary waves indicate significant effects of the solitary surface waves with interior recirculation flow on heat and mass transfer enhancement. A correlation for an average heat transfer coefficient is proposed as a function of the Reynolds and Prandt numbers based on the measurements.

• 出版日期2002