Experimental assessment of blowing effect on vehicle performance and aero-acoustics in small-rotor/wing interaction

Abstract

The tiltrotor design for urban air mobility (UAM) combines vertical take-off and landing (VTOL) capability with fixed-wing efficiency. However, it confronts challenges posed by downward force due to rotor wake effect. Previous research has employed active flow control, such as blowing air, primarily during forward flight using a single air outlet slot. However, the implications for rotor performance and aero-acoustic characteristics have remained unexplored. The experimental approach in this study involves controlled blowing air with moderate momentum in hover mode, concentrating on rotor performance, download force, noise signature, and the influence of port patterns. It is found that the radial port pattern emerges as pivotal for mitigating downward force and augmenting rotor efficiency. The efficacy of noise reduction hinges on both receiver orientation and port pattern selection. This investigation significantly contributes to understanding the role of blowing effect in optimizing tiltrotor designs, particularly in the context of rotor wake-wing interaction.