Design for urban vertical-axis wind turbines: balancing performance and noise

In urban areas, vertical-axis wind turbines (VAWTs) show promise due to their omnidirectional design, addressing challenges faced by traditional horizontal-axis turbines (HAWTs). Despite significant progress in urban VAWTs, extensive multidisciplinary research is needed to optimise their efficiency and use in such environments. <br/><br/>This...

Physics of broadband noise reduction by serrated trailing edges

Wind-turbine noise can restrict the growing implementation of renewable energy sources and their application close to urban environments. The largest contributor to the noise of modern turbines is the scattering of the turbulent fluctuations at the blade trailing edge. This source of noise is directly correlated with the turbine’s extracted...

Methodologies and algorithms for sound propagation in complex environments with application to urban air mobility: A ray acoustics approach

Aerodynamic Noise Reduction with Porous Materials: Aeroacoustics Investigations and Applications

Public annoyances due to noise emission in aviation and wind energy sectors are expected to become more severe in the near future with increasing number of civilian flights and wind turbine installations. Such trend demands for deeper investigations into the noise generation mechanisms and the means to mitigate them. This dissertation addresses...

Ducted wind turbines revisited: A computational study

Ducted Wind Turbines (DWTs) are one of the many concepts that have been proposed to improve the energy extraction from wind in comparison to bare wind turbines. In reviewing the DWT studies, investigations based on the combined use of theoretical, computational, and experimental techniques have been presented. Although indicated in these studies...

High Resolution Imaging of Noise from Novel Integrated Propeller Systems

Humans localize sound incessantly using the ears and it proves to be important of<br/>our awareness. It can also be a cause of annoyance to the community whenever<br/>sound is in the form of noise. Due to increase of wealth, industry, technology and<br/>corresponding globalization there is a large increase of noise. Especially with the<br/...

Airfoil Self-Noise - Investigation with Particle Image Velocimetry

Noise generated aerodynamically by the airflow over a lifting surface is often of concern for applications as diverse as air and ground transportation, heating, ventilation, air-conditioning systems, and wind turbines. The thesis describes the application of advanced optical flow measurements techniques for the visualization and description of...

Aeroacoustic Resonance of Slender Cavities: An experimental and numerical investigation

An experimental study on the aeroacoustics of wall-bounded flows: Sound emission from a wall-mounted cavity, coupling of time-resolved PIV and acoustic analogies

This thesis deals with the problem of noise. Sound is a constant presence in our lives. Most of the times it is something wanted and it serves a purpose, such as communication through speech or entertainment by listening to music. On the other hand, quite often sound is an annoying and unwanted by-product of some other activity necessary to us....

Aeroacoustics of compressible subsonic jets: Direct Numerical Simulation of a low Reynolds number subsonic jet and the associated sound field

Jet noise is an extensively studied phenomenon since the deployment of the first civil jet aircraft more than 50 years ago. Jet noise makes up a considerable portion of the total noise of jet aircraft, and the expansion of the numbers of airplanes and airports has only been possible by keeping the noise of airplanes under control. However, while...

Acoustic formulations for aeronautical and naval rotorcraft noise prediction based on the Ffowcs Williams and Hawkings equation