In cold regions, when spray is swept up by wave or wind action off the surface of a lake or ocean, it can adhere and freeze on marine vessels and structures. Ice accretion due to spray icing on exposed surfaces poses a serious hazard to offshore structures  and vessels, and can endanger the lives of the crew. This paper studies the impact of single fresh and saltwater droplets under typical arctic conditions in order to characterize the influence of thermophysical properties of marine substrates and coatings on the solidification process. A first order thermal resistance model is developed which includes the resistance within the post-impact drop and the transient  spreading resistance within the substrates and coatings.  The energy transfer in this study is predominantly that of latent heat to the substrate. Scaling is used to identify the dominant mechanisms and to neglect other factors such as energy transfer to the ambient, sensible energy change and the influence of kinetic energy.  
An expression for dimensionless time-to-freeze based on thermal resistance is developed which   
shows good agreement across a wide range of dimensionless time.  
Notably, when  the coating is a poor thermal conductor as is typical of marine coatings,    
the transient spreading resistance within the  surface and coating significantly influences the post-impact spread radius and time-to-freeze. By manipulating  the thermophysical properties of the substrate,  the time history of freezing in the post-impact drop and its shape  can significantly be influenced.

 


Effect of  Thermal Transport on Solidification of High Impact Salt and Freshwater Water Droplets on Marine Surfaces

Division / Sponsors: 
Heat Transfer Division (HTD), Fluids Engineering Division (FED)

Heat Transfer Summer Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/HT/HT2020/volume/83709

18th International Conference on Nanochannels, Microchannels, and Minichannels
Paper Proceedings: https://asmedigitalcollection.asme.org/ICNMM/ICNMM2020/volume/83693

Fluids Engineering Division Summer Meeting
Paper Proceedings: https://asmedigitalcollection.asme.org/FEDSM/FEDSM2020/volume/83716

HT-ICNMM2020 - Virtual Conference, SHTC - Virtual Conference, FEDSM2020 - Virtual Conference

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