Compressible Flow: Wind Tunnel

Wind Tunnel Drag Analysis — ANSYS Fluent CFD Simulation Training

This project models a wind tunnel and a specific body placed inside it using ANSYS Fluent, with the goal of investigating the drag force acting on the body.

The geometry was created in ANSYS Design Modeler® and meshed in ANSYS Meshing® using an unstructured grid, for a total of 179,542 elements.

Background

The wind tunnel is one of the most widely used aerodynamic testing tools in use today. Among the many experiments it enables are tests of various structures, including airfoils, aircraft, and static bodies. These experiments are typically aimed at studying aerodynamic behavior and visualizing the flow lines around the test object.

Wind tunnels can also be used for free-fall tests, examining how airflow affects a falling object. Because forces such as drag have a significant influence on a body's behavior, quantifying them is essential — and CFD provides an effective means of doing so.

Methodology

A density-based (compressible flow) solver is used in this simulation, and the energy equation is activated accordingly to capture the compressible-flow physics.

Results

The solution produces contours of velocity, pressure, temperature, and related quantities for a range of inlet Mach numbers. The velocity vectors reveal the formation of separation vortices behind the body. As a result of this separation, the flow turbulence in the wake is substantial — noticeably greater than in the rest of the computational domain.