F-16: Inviscid Supersonic Flow

Inviscid Supersonic Flow Over F-16 Aircraft Simulation

Description

This project simulates supersonic inviscid flow over an F-16 fighter aircraft using ANSYS Fluent. Flying at 400 m/s — approximately Mach 1.16, comfortably above the speed of sound — the aircraft experiences a flow field dominated by pressure and inertial effects rather than viscosity. By treating the fluid as inviscid (zero shear stress), the simulation isolates the pressure-driven physics responsible for aerodynamic lift, making it a clear illustration of the fundamentals of high-speed external aerodynamics.

Since supersonic flow is inherently compressible, the Mach number serves as the key parameter quantifying this compressibility throughout the simulation. Assuming inviscid flow simplifies the governing Navier-Stokes equations toward Bernoulli's equation, allowing the pressure and velocity fields to be resolved without the added cost of capturing boundary-layer effects.

The 3D F-16 aircraft geometry was imported and positioned within a flow enclosure using SpaceClaim, and the surrounding domain was meshed in Fluent Meshing using an unstructured grid of approximately 979,000 elements.

Methodology

The simulation employs the inviscid viscous model, with air density defined via the ideal gas law to appropriately capture compressible behavior at supersonic speed.

A key methodological choice in this simulation is the use of a pressure-based solver with coupled pressure-velocity coupling, rather than the more commonly expected density-based solver typically used for supersonic cases. This approach helps avoid common convergence difficulties that can arise at supersonic speeds, offering a more robust path to a converged solution for this geometry.

Conclusion

Post-processed pressure and velocity contours reveal the high-pressure region forming beneath the wings — the primary source of aerodynamic lift in this configuration. The results also illustrate the tightly coupled relationship between pressure, density, and temperature that characterizes compressible flow behavior.

Inviscid supersonic analysis of this kind provides a fast, computationally efficient first step in aircraft and missile aerodynamic design, delivering lift and pressure distribution insights without the added cost of resolving boundary layers. The pressure-based solver technique demonstrated here is a genuinely useful approach for stabilizing otherwise difficult high-speed compressible simulations.