Effect of Variable Melting Temperature on the Enthalpy Model for Runway Deicing

Abstract

<div class="section abstract"><div class="htmlview paragraph">One of the most significant challenges for the aviation industry in the winter is the deicing operations on runways. As a result, deicer chemicals can pollute the environment if used in a large amount. A mathematical model could help optimize the use of deicer chemicals. Road deicing models exist to predict pavement temperature covered by snow/ice during deicing operations. However, the specificity of airport operations requires a model for the runway deicing to simulate the mass of ice melted with usage of deicing agents. Here we propose a model for runway deicing and validate it against experimental results. Our model considers temperature, diffusive flux, and time changes in a normal direction. It also calculates the mass and heat transfer in three regions (liquid, mushy, and solid). We used the enthalpy method to determine the temperature and the interface location at each time step. In the liquid and solid, the deicer concentration is obtained by Fick’s law and updated at each time step and location. The melting point temperature is variable due to the dilution of the deicer in the solution. Therefore, melting points are updated depending on the concentration at each location and time. The model uses the phases diagram for water and deicer agent mixture, considering eutectic point, for melting point calculation. The mesh dependency of the model is first investigated. To verify the model sensitivity, the paper proposes parametric studies for the heat transfer coefficient and the diffusion coefficients. Then, to validate the model, the Anti-Icing Materials International Laboratory (AMIL) in Chicoutimi conducted experimental tests on deicer agents for runways. Validation of the model is achieved for potassium acetate and potassium formate, two types of deicers.</div></div>