FSI Analysis of NACA 0014 Airfoil: Aerodynamic Forces and Structural Response

Description

In this project, we present a simulation of an Airfoil exposed to the airflow via ANSYS Fluent software.

Since the airfoil is exposed to airflow, an interaction occurs between the wind blowing and the airfoil structure. It means that airflow exerts a volume force on the airfoil's body by hitting it. Therefore, we intend to perform a numerical simulation of the airfoil as a Fluid-Structure Interaction (called FSI).

The interaction between fluid and structure can be implemented as:

• One-way FSI

• Two-way FSI

In this project, we aim to analyze only the effect of fluid on the structure, and there is no need to account for the effect of the structure on the fluid. So, we choose One-way FSI, which is a simple and less-expensive approach.

We modeled the geometry via SpaceClaim software. The computational domain is a sample space of the surrounding air that includes both fluid and solid domains. There is a solid airfoil structure within the fluid environment, which is considered fixed from the center.

We meshed the computational domain via ANSYS Meshing software. The mesh is of an unstructured type, and approximately 1,700,000 cells have been generated.

Methodology

Fluid-structure interaction can be performed in two general methodologies:

• In the ANSYS Workbench environment, using an external solver (specifically, system coupling)

• Only in the Fluent solver (in the form of an intrinsic FSI).

In this project, we implemented a one-way FSI in the ANSYS Fluent environment. In other words, the Fluent solver performs both fluid and solid calculations simultaneously.

For two-way FSI in Fluent solver, the Structure model is utilized. The structural model can be implemented in two ways:

• Linear elasticity: The deformation is proportional to the applied force. In this case, the deformations are usually small, and the calculation process is faster.

• Nonlinear elasticity: The deformation is not necessarily proportional to the applied force. In this case, the deformations are usually large, and the calculation process is more complex and time-consuming.

In this project, we considered fluid-structure interaction in the form of a Linear Elasticity state.

Since we were analyzing one-way FSI and not considering the effect of structural displacement on the adjacent fluid, we didn't need to use the dynamic mesh model.

Results

We analyzed the results in two fluid and solid approaches:

In a fluid view, we studied the behavior of airflow. For this, we obtained the distributions of the pressure and velocity of air. The results show that the airflow collides with the airfoil body at high speed and, as a result, exerts a hydraulic force on the airfoil structure.

In a solid view, we studied the behavior of the airfoil body under the influence of the applied forces of the air flow. For this, we obtained the distribution of the von Mises stress and displacements (in all directions). The results confirm that the airflow affects the airfoil structure and, as a result, it undergoes displacements relative to the fixed center.

In conclusion, we can claim that we carried out the simulation project of an airfoil correctly and acceptably by using the two-way FSI method.