SEA SPRAY ICING: IN-CLOUD EVAPORATION. SEMI-ANALYTICAL AND NUMERICAL INVESTIGATIONS.

摘要

Interactions between waves and a ship produce sprays of scawater that may freeze on the surfaces of the ship. Simulations of water spray flow in the air are important for the understanding and assessment of ice accretion on offshore structures and ships. During the spray flow, the spray evaporates, and the humidity of the surrounding air may increase. The increased humidity may affect the evaporation process and the thermodynamics of the spray. This study numerically investigated the influence of increased humidity on the in-flight spray temperature and mass change. Using ANSYS Fluent and semi-analytical calculations, the process was studied for the conditions of constant wind speed and likely temperatures and humidity levels for offshore conditions. The input properties of the sea spray cloud were based on field measurements. When disregarding the air humidity change, the error of the spray temperature is approximately 0.5℃ for a cloud with a concentration of 50 g/m3 if we assume no diffusion of water vapour out of the cloud. This work is part of the MARICE project conducted by Det Norske Veritas (DNV).