Numerical study of falling film flow on a horizontal rotating tube

Abstract

In this paper, a CFD simulation of falling film on a horizontal rotating tube is illustrated. The objective of this simulation is to explore the influence of various parameters on this kind flow. The simulation results show that in a certain range, the offset angle of the liquid column increases with the increase of the rotational speed, which agrees well with the experimental values. Compared to a stationary tube, the liquid film thickness at the left side of the liquid column is thinner but the right gets larger when the tube is rotating counterclockwise. And the liquid film velocity at the left side of the liquid column is equivalent to the linear superposition of the velocity at the standstill and the rotational velocity denoted by ω. Rotation has a great influence on the velocity distribution at the right side of liquid column. Increasing the rotational speed and the diameter, decreasing the inlet velocity and the inlet hole diameter will make the offset angle of the liquid film larger. The high temperature reduces the offset angle of the liquid column, and the gradient of the liquid column offset angle to temperature becomes smaller. When the temperature is above 65 °C, the effect of temperature on the offset angle of liquid column is negligible. When ω = 200 rpm, the offset angle increases first and then decreases with the increase of the inlet height, but when ω = 300 rpm, the offset angle increases with the increase of the inlet height.