Aerial Structure: LES

Compressible Flow around an Aerial Structure, LES CFD Simulation, ANSYS Fluent Training

Description

This project simulates compressible flow around an aerial structure using ANSYS Fluent. The airflow moves horizontally at 300 K, Mach 5, and atmospheric pressure within the computational domain. The 3D geometry was designed in Design Modeler, representing the aerial structure positioned within a rectangular cube-shaped computational domain. Given the model's perfectly symmetrical structure, only half the geometry was modeled, with a symmetry condition applied along the symmetry plane.

The domain was meshed in ANSYS Meshing using an unstructured grid totaling 5,515,041 elements.

Methodology

A density-based solver was used to capture the airflow behavior, appropriate given the fully compressible nature of the flow. Density-based solution approaches are commonly applied to models involving acoustic waves, shock wave phenomena, airfoils in supersonic conditions, and any case where density variation plays a significant role.

The computational domain's side walls were all assigned a pressure far-field boundary condition, with air defined as an ideal gas, so that density varies as a function of pressure, velocity, and temperature according to the ideal gas relationship. The simulation was run as unsteady (transient), with turbulence captured using Large Eddy Simulation (LES).

Conclusion

Results include 2D contours of pressure, velocity, temperature, density, and Mach number. The results clearly demonstrate the compressible nature of the airflow around the aerial structure, with air density varying substantially in response to the pressure and velocity changes occurring in the flow field surrounding the structure — confirming the strongly compressible behavior expected at this Mach 5 flow condition.