Electronic Thesis and Dissertation Repository


Master of Engineering Science


Mechanical and Materials Engineering


Dr. Kamran Siddiqui


An experimental investigation of flow over a complex topography was undertaken to study the influence of inflow conditions including Reynolds number, upstream roughness, and inflow shear profile on mean and turbulent flow behaviour.

Large-scale physical testing was employed over the escarpment of a hill, covering a Reynolds number range of 3.6×104 to 5.2×105. Measurements taken using Particle Image Velocimetry (PIV) and Cobra Probes were analyzed in terms of mean and turbulent statistics. Coherent structures were characterized through Proper Orthogonal Decomposition (POD).

The results show that the Reynolds number had little effect on the flow behaviour, while the effect of changing upstream roughness was low to moderate. The modified inflow shear profile had a significant impact, greatly increasing turbulent kinetic energy. A sharper escarpment leading edge had the largest impact by far, significantly altering the flow dynamics. The turbulent flow behavior over the sharper escarpment was found to be similar to the classical case of forward-facing step.