3-D Airfoil CFD Simulation, ANSYS Fluent Training

Description

3-D Airfoil CFD Simulation

An airfoil is the cross-sectional shape of a wing, a propeller rotor or turbine blade, or sail as seen in cross-section.

An airfoil is a streamlined shape that is capable of generating significantly more lift than drag. Subsonic flight airfoils have a characteristic shape with a rounded leading edge, followed by a sharp trailing edge, often with a symmetric curvature of upper and lower surfaces. Foils of similar function designed with water as the working fluid are called hydrofoils.

In this study, a CFD solver is employed to test an airfoil for ourselves, and the drag and lift force values were calculated by ANSYS Fluent software.

Project Description

This project is going to study an incompressible isothermal air flow adjacent to a 3-D airfoil. The geometry is a 1-meter airfoil inside a 20-meter wind tunnel. Also, the maximum speed of 10 m/s is selected for the inlet.

Geometry and Mesh

As a numerical study, the initial step towards the modeling is the production of the CAD geometry, depicted below. The blue face is considered the inlet of the domain, while the red face on the other side is considered the outlet.

For the current problem, a mesh count of 724,682 elements was created to represent the geometry. Regarding the quality of the mesh, the maximum skewness of 0.93 with an average of 0.28 is a satisfactory mesh for the current problem. In addition, for an interested reader, the quality distribution of mesh is shown as follows. Also, 15 prism layers were added adjacent to both tunnel walls and the airfoil body to calculate the boundary layer accurately.

CFD Simulation Settings

By importing the mesh into the ANSYS FLUENT solver, the calculation procedure is started. The Details of the solution setup are as follows:

Table (1)- Solver Settings

3-D Airfoil CFD Simulation Results and Discussions

After the solution convergence, they can observe the results through post-processing. Meanwhile, as an assurance of a valid convergence, we monitor the drag and lift values during the solution iterations. In this study, the solution was a converged one when the drag force reached a constant rate and the residuals were below 10^-7 values.

Afterward, the results regarding the pressure and the velocity field are depicted in the below figures. Again, the maximum value of velocity was found at the top surface of the airfoil, while the maximum value of pressure was at the leading edge where the velocity was minimum. Also, the streamlines were shown to give much insight into the problem.

Finally, we calculated the drag and lift force at 4.91 and 19.61 (N), respectively, which was accurate for a 1-meter airfoil with the noted specifications.