Study on liquid film thickness and flow characteristics of falling film outside an elliptical tube

Abstract

A three-dimensional model is applied to simulate the spreading process and thickness distribution of the liquid film outside an elliptical horizontal tube falling-film heat exchanger. Reynolds number (Re) is 187 and the counter-current air flow rates are 0, 0.1 and 0.5 m/s, respectively. The volume of fluid method is used to trace the gas-liquid interface. It is shown that falling film flow delays and the liquid film thickness increases as the gas flow rate increases. When the counter-current gas flow rate is increased to 0.5 m/s, the falling film distribution becomes uneven and local accumulation occurs. Along the circumferential direction, the liquid film velocity increases as the gas flow rate increases.