CFD-Based Aerodynamic Stability Analysis of a Quadrotor UAV

This study analyzes the aerodynamic stability of a typical quadrotor UAV during hover and vertical flight using Computational Fluid Dynamics (CFD). A fitted relationship between single propeller rotational speed versus lift and torque was obtained through simulation. Rotor speed input parameters were determined by combining this relationship with force analysis under ideal conditions. Lift and torque variation data for each rotor under two typical flight conditions were subsequently acquired. The research examines changes in lift and torque caused by aerodynamic interference between rotors, which induces UAV instability. To address the additional rotor lift from airframe obstruction of airflow, a “Reduction Value Method” is proposed to correct the lift data.

Kinematic simulations conducted in Adams show significant displacement and angular displacement fluctuations in both hover and vertical flight states. Instability is more pronounced during vertical motion. This research provides a theoretical basis for understanding UAV flight stability mechanisms and optimizing control strategies.