Moving Mesh (Mesh Motion): Helicopter

What You'll Build

This lesson walks you through a CFD simulation of rotating helicopter rotor blades using the Mesh Motion technique in a transient formulation. A helicopter stays aloft by forcing a large mass of air downward through its rotating blades, generating an equal and opposite upward force. By aerodynamically shaping the blades and spinning them, the rotor raises the air pressure beneath the wing and creates lift.

In this project, you'll model that rotating rotor and quantify the net upward force, blade tip speed, and Tip Speed Ratio.

What You'll Learn

• The physics of helicopter lift — how downward air movement produces upward thrust

• How a rotor of two or more wing-shaped blades generates a pressure difference across the blade

• How to design a 3-D rotor and surrounding domain in Design Modeler

• How to generate a mesh (~937,677 elements) in ANSYS Meshing

• How to use the Mesh Motion method to simulate continuous blade rotation at 1250 rpm about the Y-axis

• Why a transient solver is required to capture the rotating motion over time

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

• How to post-process velocity, pressure, turbulent viscosity contours, and streamlines, observing the swirling air motion induced by the blades

• How to extract key performance metrics: the pressure difference across the rotor (5 Pa), maximum domain air velocity (2 m/s), and blade tip velocity (1.96 m/s)

Why It Matters

Mesh Motion is a core technique for any continuously rotating machinery analyzed in transient mode — helicopter rotors, propellers, wind turbines, and mixers. The rotating-flow workflow you build here gives you a foundation for rotorcraft aerodynamics and rotating-blade performance studies.