Enhancement of Aeroacoustic Testing: Applied to closed-section wind tunnels

Aeroacoustic testing in wind tunnels is crucial for understanding and mitigating the noise generation mechanisms in several devices while maintaining satisfactory aerodynamic performance in the conceptual design stage. However, current measurements in closed-section wind tunnels face challenges in terms of installation, due to the effect of the...

Aeroacoustics of Airborne Wind Energy Systems

Airborne wind energy systems offer a promising approach for renewable energy generation. However, the noise emissions associated with these systems should be understood and minimized as well to promote their integration and (social) acceptance. This research aims to identify the noise sources of airborne wind energy systems, systems with leading...

Attenuating Jet Installation Noise with a Lobed Nozzle: Master of Science Thesis

Over the last few decades, the bypass ratio and nacelle diameter of modern turbofans have been increasing to achieve higher efficiencies. This trend has forced the underwing-mounted engines to be coupled more closely to the wing surface and the flap system, which significantly enhances the low-frequency noise, known as jet installation noise ...

Noise radiation of a low Reynolds propeller at an angle of attack: an experimental and analytical study

This work presents an experimental and analytical investigation of unsteady loading of a low Reynolds number propeller and its relation to aeroacoustics. The propeller is positioned at an angle of attack with respect to the freestream which causes a variation in loading along the azimuth. The propeller is operated at 4000 RPM with an advance...

Equivalent Fluid Modelling of a Honeycomb Acoustic Liner using the Acoustic Porous Medium Formulation

Over the past decades, numerous methods have been used to study acoustic liners through their impedance, of which numerical methods are of particular interest. Despite their advantages, numerical methods are bounded by certain drawbacks. One such drawback stems from the need to accurately discretize the liner geometry, which can lead to large...

Computational Aeroacoustic Investigation of Co-rotating rotors for Urban Air Mobility

Noise is a major issue in Urban Air Mobility vehicles, especially due to its operation in the urban environment. One of the major sources of noise is the rotor, and thus, there is a need to optimize the rotor design for aerodynamics and aeroacoustics. A possible technological solution is represented by Co-rotating rotors (i.e., two rotors...

Numerical and Experimental Study of Airfoils with Porous Trailing Edge

The addition of porous material to the trailing edge of airfoils was studied numerically and experimentally. The purpose of this work is to inspect whether the penalization method can be successfully used to describe flows through porous media. In the numerical study, the penalization method was applied to the incompressible Navier-Stokes...

Unsteady Pylon Loading for Pylon-Mounted Tractor Propellers

Aeroacoustics and Flow Dynamics of an airfoil with a Gurney flap using TR-PIV

Aircraft noise has come under severe scrutiny due to growing number of airports and airline operations. The noise generated by high lift devices is now comparable to the turbofan engines due to increasing bypass ratios. A Gurney flap is a suitable starting point to study trailing edge flap aeroacoustics due to additional lift characteristics and...

Flap Side-Edge Noise Reduction