Abstract:
The dynamic aerodynamic characteristics of rotor airfoils are a key research focus in helicopter aerodynamics,Traditional rotor airfoil dynamic tests typically rely on driving the airfoil model to perform sinusoidal oscillatory motion to generate dynamic flow effects,but the model motion differs from real flight conditions.To better reflect the dynamic aerodynamic characteristics of rotor blade sections under rotating motion conditions,this study is based on the blade element theory for helicopter forward flight, the effective angle of attack variation curve at the 70% section of the rotor blade in real condition was obtained by analyzing to actual helicopter flight data,full-scale wind tunnel data,and computational data,a similarity transformation was then applied to derive the corresponding angle of attack variation curve for wind tunnel testing. Finally, the airfoil non-sinusoidal periodic dynamic test for this curve was carried out based on the FL-54 wind tunnel.A comparison between the experimental data and traditional sinusoidal dynamic test results provides clearer insights into the influence of angle of attack variations on airfoil aerodynamic forces.This study provides data support closer to actual flight conditions for the design and optimization of rotor airfoils.