Thin Film: Deicing and Defogging
The Thin Film model provides a simplified approach for simulating deicing or defogging inside a cabin windshield or other surface. It addresses cases where the only features of interest about the ice or fog layer are where the layer is distributed and how thick it is. It assumes that the thickness is negligible compared to cell size.
For an example where the changing layer thickness is geometrically and dynamically significant, see the tutorial Dispersed Multiphase: Airfoil Icing. This tutorial describes ice accumulation on an airfoil, which changes shape as the ice layer grows.
This section covers the following:
- The Thin Film model
- The Deicing and Defogging models
- The Deicing and Defogging solvers
Also included is the following reference information:
- Boundary conditions
- Boundary values and initial conditions
- Field functions that this model activates
The Thin Film Model
The Thin Film model provides a simplified approach for simulating deicing or defogging inside a cabin windshield or other surface. This model has no properties.

The limitations on the Thin Film models are as follows:
- Thin Film Model
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- This model is not compatible with the Eulerian Multiphase models, that is, Eulerian Multiphase (EMP), Volume of Fluid (VOF), and Mixture Multiphase (MMP).
- Once a boundary is switched from deactivated to having a fog or ice layer, the simulation must be run in transient mode.
- It is possible to have Deicing and Defogging in the same region, but not on the same boundary.
- Deicing Model
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- You cannot use a contact boundary. Deicing can only be applied to wall boundaries and the type must be convection or heat flux.
- Defogging Model
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- Defogging can only be applied to wall and contact interfaces (solid/fluid).
- Currently the saturation vapor pressure curve is based on water vapor.