Study on flow and noise characteristics of composite NACA64418 blade under different inlet velocities

Abstract

This paper conducts an analytical study on the composite NACA64418 blade. The study uses the large eddy simulation (LES) method to calculate the unsteady flow field of NACA64418 at different inlet velocities, and the trend of flow field characteristics with different inlet velocities was analysed. It was found that the energy characteristics of the wing increased continuously with the growth in velocity. However, based on the trend of the lift-to-drag ratio, it is presumed that the lift-to-drag ratio will eventually remain constant or may even decrease when a certain inlet velocity is reached. The Q-criteria was used to identify the vortex structure. It is found that the flow state on the wing surface at high velocities can be clearly distinguished according to the vortex morphology, containing laminar, transitional and turbulent regions. Finally, the aerodynamic noise of the far-field wing is obtained by solving the Ffowcs Williams-Hawkings (FW-H) equation, and the noise characteristics are analysed. We obtain that the noise around the wing increases with the increase of velocity. The noise value increases more significant in Φ=90° and 270°, but the noise increase ratio is more evident in Φ=0° and 180°.