Experimental Characterization and Analytical Modelling of Rotor Tonal Noise

Rotors have played a huge role in the history of the aerospace industry. It is being widely used in small scale aircraft, helicopters, ships, wind turbines, to name a few. The study of noise generated by the rotors is an important subject of research. This project aims to characterize the open rotor tonal noise using the experimental and...

Experimental Investigation of Fan-Stage Interaction Noise of a Turbofan Engine

Future designs of turbofan engines are heading towards High By-Pass Ratios (HBPR) to satisfy the requirements of improving the overall efficiency, but there is an inherent acoustic penalty related to this. An increase in the by-pass ratio imposes structural constraints on the engine leading to a decrease in the axial distance between the rotor...

Active acoustic metamaterial based on Helmholtz resonators to absorb broadband low frequency noise

Metamaterials are a new class of materials that have properties that cannot be found in nature. Though these artificially engineered structures have not been prominently used in many applications, they have been theoretically studied to have a variety of applications in many sectors. Acoustic metamaterials have the capability of manipulating...

Identiffcation of Momentum Forcing Required to Reduce Base-Model Errors Using Full-Field Inversion

Reynolds Averaged Navier-Stokes turbulence models have been widely used in many industrial applications because of their lower computational cost compared to other simulation approaches such as DNS and LES. This is a consequence of considering mean-ow quantities achieved by the time-averaging process. However, the time-averaging introduces the...

Aeroacoustic investigation of a stridor patient’s upper respiratory system: A Lattice Boltzmann Method simulation using Exa PowerFLOW

Children and adults suffering from Upper Airway Obstructions (UAOs) are nowadays examined using an invasive endoscopy. Because this diagnostic technique unavoidably exposes the patient to certain health risks, there exists a clear need for a non-intrusive diagnostic tool. Several research programs have been initiated that aim at the development...

The Effect of Leading Edge Thickness on the Maximum Drag Coefficient of Airfoils at 90 0 Angle of Attack: Experimental and Computational Analysis of Designed Profiles subjected to Extreme High Angles of Attack

The need for energy is an ever increasing problem and most resources that are used today will be exhausted or no longer tolerated by the human kind in the future Omer (2008). Anticipating on the energy demand the development of wind turbines has taken a big leap and to improve the design process efficient and accurate aerodynamic modelling is...

Assessment, Development and Validation of Wind Turbine Rotor Noise Prediction Codes

Wind turbine noise has become an important issue when developing onshore<br/>wind farms as turbines have scale up rapidly in the latest decades. The interest of this project is focused on the characterization and modelling of noise as a source based on the specific physics from wind turbines. A dedicated evaluation of wind turbine noise...

Exploration of Ensemble Kalman Filter for parameter estimation with plasma actuators: Twin experiment and application using experimentally obtained quasi-steady ow fields

This thesis aims to explore and enable parameter estimation using the data assimilation method of the ensemble Kalman filter (EnKF). More specillically applied to the quasi-steady flow field, measured using particle image velocimetry (PIV), of a plasma actuator in quiescent ow where the parameters to be estimated are those describing the force...

Dielectric Barrier Discharge Plasma Actuators for Unsteady Aerodynamic Load Control

Active load control for load alleviation has become more important in the wind energy industry in recent years. The continuously increasing size of wind turbines has eventually led to the point where efficient mitigation of the fatigue loads on the blades, due to unsteady wind or gusts, is becoming an important aspect in the design. Suppression...

Active Control of Natural Tollmien-Schlichting Waves using DBD Plasma Actuators

Understanding, predicting and controlling laminar to turbulent transition is of great interest due to the wide range of practical applications where transition is significant. Generally, turbulent flow has an order of magnitude higher skin friction. Fuel savings of up to 25% would be possible for a large commercial aircraft if laminar flow could...

Aeroacoustic Investigation of Beveled Trailing Edges by High-Speed Particle Image Velocimetry

The aerodynamic noise generated by trailing edge of aircraft wings at take-o_ and approach con_guration continues to be a critical factor in the future development of aviation. Trailing edge noise is also a serious concern for wind turbines, marine propellers, helicopter rotors, axial and centrifugal turbines and compressors. A fundamental...

Wake Bursting Effects of a Drooped Spoiler Panel in a Wing-Flap Configuration: An Experimental Investigation

Nowadays, the evolution of multi-element airfoils presents a change of route, towards a "circular arch", in order to achieve the ultimate lift force [9]. Particularly, for wing-ap configurations, the enhancement of high lift performance, is of great interest and growing research at Delft University of Technology. Typically, the main approach...