Candidate for a Doctor of Philosophy in Mechanical Engineering. Research is conducted as a part of the Wind Energy Research Group at the University of Waterloo under the supervision of Professor David A. Johnson
This site summarizes the work completed to date for the completion of the PhD degree, as well as the research completed for the Master of Applied Science degree recieved from work conducted in the same research group. The focus of this research is the application of computational fluid dynamics (CFD) and computational aeroacoutsics (CAA) to low Reynolds Number airfoil self-noise, with the overall goal of gaining a deeper understanding of the ability of these models to predict the aeroacoustic noise produced by small wind turbines. The models used are Large Eddy Simulation (LES) and Ffowcs-Williams and Hawkings (FW-H) to predict the flow and acoustic behaviour, respecitvely.
The MASc work tested the models' predictive ability for airfoils at static angles of attack (AOAs) and compared the results with existing aerodynamic and aeroacoustic experimental data collected by the UW Wind Energy Research Group. The in-progress doctoral research investigates the transitional separated boundary layer (BL) on the suction side of the airfoil and how that behaviour relates to the aeroacoustic noise. This process includes a laminar separation bubble (LSB) and occurs during the natural (unforced) BL transition, and is very sensitive to the inflow conditions of the airfoil as well as the meshing and simulation parameters for the LES model. The accurate simulation of the BL transition process is crucial to the aeroacoustic prediction, since frequencies of structures formed within the transitioning BL are closely tied to the resulting tonal noise frequencies.
Additional work applies the unsteady Reynolds-averaged Navier-Stokes (URANS) model to low Reynolds number oscillating airfoils, which replicates the unsteady effect of blade rotation in small wind turbines. The main concern under this flow condition is the phenomena of deep dynamic stall, which can negatively impact the power production of the turbine as well as increase the unsteady loading and fatigue of the wind turbine blades.
