Evolution of turbulent liquid films on the corrugated plate-rivulets and slender water columns necking rupture

The evolution of turbulent liquid film on the corrugated plate is experimentally studied with the help of ultrasonic Doppler velocimetry and a high-speed camera, revealing the formation mechanism of rivulets and water columns necking rupture. The results show that the flow pattern of the liquid film on the corrugated plate is divided into three regions: stable region, fluctuating region, and oscillating region. In the fluctuating region, the connection between adjacent solitary waves leads to the generation of primary rivulets. In contrast, the formation of secondary rivulets mainly comes from the extinction of solitary waves. In the oscillating region, the collision between secondary rivulets promotes the formation of slender water columns. The necking diameter of the water column tended to decrease exponentially with time. The increase in Re-l (liquid phase Reynolds number) promotes the necking rupture process of the water column due to the presence of corrugated structures. When Re-l increased from 1.72x10(4) to 2.57x10(4), the characteristic time of necking rupture was shortened by about 25.7%.