An experimental study on ice melting processes under point-source bubble flows at different flow rates

Abstract

The anti-/de-icing capability of ships and offshore structures in the polar regions is of importance to ensure the safety of operation. The bubble anti-/de-icing method has great application potential. Here, a point-source bubbler system is developed to study the ice melting processes under point-source bubble flows, especially ice melting stage, bubble distribution, ice melting rate, and final ice morphology. The ice melting process is divided into flat, concave, and holed ice stages. With the increase of the flow rate, the duration of the ice melting process gradually decreases while that of the flat ice stage increases and that of the concave ice stage decreases. The number density of bubbles at the concave ice stage is the smallest and the average contact area of bubbles at the concave ice stag is the largest of the three stages. The average contact areas of bubbles at 1.0 L/min and 1.5 L/min are significantly larger than those at 0.5 L/min and 2.0 L/min at the concave ice stage. When the flow rate increases from 0.5 L/min to 2.0 L/min, the melting rate in the height direction increases by 95.4 % while the melting rate in the radial direction increases by 61.8 %. The cross-sectional profile of the final ice morphology gradually becomes steeper as the flow rate rises. The findings of this work provide insights into the ice melting mechanism under bubble flows and are helpful to the optimization of related applications.