Flow patterns and wavelength measurement for liquid film falling around horizontal tube

The present study is an experimental investigation for the hydrodynamic of a liquid film falling outside a horizontal tube. By varying the flow rate, many flow regimes are identified. The transitions between different falling-film modes are studied and compared with results of other research. The wavelengths have been measured for each film Reynolds number value for droplets and column modes and the hysteresis phenomenon is observed. The measured dimensionless wavelengths are compared to the results of Hu and Jacobi (1998) and Louahlias Gualous (2003).