Icing of a 3-D Airfoil Surface CFD Simulation, ANSYS Fluent Tutorial

Description

The present problem simulates the airflow around the airfoil and creates a water film on the surface of the airfoil body using ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

In fact, when moisturized air and water droplets hit the surface of the airfoil, a water film may form on the airfoil surface.

The purpose of this work is to investigate the thickness of the produced and flowing fluid layer on the airfoil body; This is because the presence of this layer of film on the fuselage of the aircraft can cause water droplets to freeze on the surface of the airfoil at very low temperatures.

In the present simulation, the primary phase of the Eulerian model is air and its secondary phase is liquid water droplets, which are also defined as the constituents of the Eulerian liquid film.

The mixture of airflow and water droplets moves towards the airfoil body at a speed of 30 /.s and a temperature of 250 K; So that the volume fraction of water droplets is equal to 0.002.

The boundary condition of the airfoil wall is defined in such a way that in the initial state, the liquid film has a specific height and zero velocity. The simulation process was performed in 1s with a time step size equal to 0.0001s.

The present model is designed in three dimensions using Design Modeler software. The meshing of the model has been done using ANSYS Meshing software and the mesh type is unstructured. The element number is 978532.

Icing Methodology

The Eulerian wall film (EWF) model was used to simulate and estimate the amount of liquid film produced. This model is used to estimate the formation or flow of a thin film of liquid on the wall surfaces. This model can only be used for 3D geometric models and to use it, the Eulerian multi-phase model must be activated.

Unlike other models in the software (such as the VOF model and radiation model, etc.), the Eulerian wall film model has the ability to correct the initial boundary conditions on the walls and, therefore, has a good interaction with the liquid films.

Icing Conclusion

At the end of the solution process, two-dimensional contours related to density, pressure, water velocity, air velocity, water volume fraction and air volume fraction are obtained. The contour of the thickness of the film created on the body of the airfoil is also obtained.

All contours correspond to the last second of the simulation process. The contours clearly show that the purpose of this project, ie icing, is well done and the ice layer is formed.