Fan: Axial Flow Fan Stage, Aerodynamic Performance

What You'll Build

This lesson walks you through a CFD simulation of an axial flow fan stage — a rotor–stator assembly that produces steady airflow for industrial applications such as cooling freshly painted body parts. The rotor's spinning blades accelerate the incoming air, and the stationary stator blades then straighten the flow so it exits roughly normal to the outlet. This is a classic, approachable introduction to turbomachinery CFD.

In this project, you'll model both the rotating and stationary zones and evaluate the fan stage's aerodynamic performance.

What You'll Learn

• How an axial fan stage works — the division of labor between rotor (adds energy and swirl) and stator (redirects flow)

• How to design a 3-D rotor–stator geometry in Design Modeler, defining separate rotating and stationary zones

• How to generate a mesh (~244,675 cells) in ANSYS Meshing

• How to use a periodic boundary condition to model only a slice of the fan, dramatically reducing computational cost

• How to set up the MRF (Moving Reference Frame) method to simulate the rotor's rotation at 1800 rpm while keeping the stator fixed

• How to apply the standard k-ε turbulence model for the rotating flow field

• How to post-process 2-D and 3-D pressure, velocity, streamline, and velocity-vector results, clearly visualizing the swirl induced by the rotor

• How to calculate key turbomachinery performance metrics: rotor tip linear velocity (~31 m/s), Tip Speed Ratio (TSR = 4), and outlet airflow rate (16.14 lit/s)

Why It Matters

Fans, compressors, pumps, and turbines all rely on rotor–stator interaction. The MRF + periodic-boundary workflow you learn here is the standard, cost-efficient approach to turbomachinery analysis — directly transferable to blowers, axial compressors, and ventilation fans.