Recent Advances in Airfoil Self-Noise Passive Reduction

Abstract

Airflow-induced noise prediction and reduction is one of the priorities for both the energy and aviation industries. This review paper provides valuable insights into flow-induced noise computation, prediction, and optimization methods with state-of-the-art efforts in passive noise reduction on airfoils, blades, and wings. This review covers the combination of several approaches in this field, including analytical, numerical, empirical, semi-empirical, artificial intelligence, and optimization methods. Under passive noise reduction techniques, leading and trailing edge treatments, porous materials, controlled diffusion airfoils, morphing wings, surface treatments, and other unique geometries that researchers developed are among the design modification methods discussed here. This work highlights the benefits of incorporating multiple techniques to achieve the best results concerning the desired application and design. In addition, this work provides an overview of the advantages and disadvantages of each tool, with a particular emphasis on the possible challenges when implementing them. The methods and techniques discussed herein will help increase the acoustic efficiency of aerial structures, making them a beneficial resource for researchers, engineers, and other professionals working in aviation noise reduction.

Quantitative analysis of predictors of acoustic materials for noise reduction as sustainable strategies for materials in the automotive industry

“…Acoustic comfort in aircrafts is a major concern in the aerospace industry [69]. Studies and research in the field [70][71][72][73][74][75] aim to develop technologies and solutions for passive noise control, including through the improvement of absorbent materials, design, and other interior components. Additionally, advanced methods of analysis and numerical simulation are used to assess the impact of different configurations and materials on cabin noise levels and to optimize the aircraft's interior design to enhance acoustic comfort.…”

Effects of an Owl Airfoil on the Aeroacoustics of a Small Wind Turbine

“…Inflow-turbulence noise does therefore depend on atmospheric turbulence, and the airfoil self-noise becomes the dominant source with less atmospheric turbulence or none. Airfoil self-noise is also of a broadband character, resulting from the interaction of the turbine blade surfaces with the turbulent boundary layer of the viscous flow [19][20][21]. The airfoil self-noise radiating from the trailing edge, for example, is increased by the thickness of the trailing edge.…”

Numerical Investigation and Optimization of a Morphing Airfoil Designed for Lower Reynolds Number

“…Initial passive approaches, including lift increasing devices (such as flaps and slats) or winglets (meant to decrease the negative effects of tip vortices), have been employed on wings and blades for decades and have demonstrated their benefits [9]. They also proved extremely significant for noise generation and regulation [10]. More recent research and engineering efforts have turned to active leading and trailing parts capable of changing their shape, as described in [11].…”