"The project was divided in two main work packages, one focused on the measurements of the drag and flow structure around complex topologies in a wind tunnel and the second on dispersion measurements in a water tunnel.
For WP1, experiments were conducted in the 3'x2' boundary layer wind tunnel at the University of Southampton. To prepare for these experiments, multiple fractal-inspired rough patches were designed in a parametric way, in order to study the effects of frontal and planform solidity, then 3D printed. Calibration of the wind flow and the custom-built drag balance were also completed in advance of the wind tunnel testing. The experiments were then completed to measure the drag force and flow patterns over a set of roughness patches in order to determine the sensitivity of drag versus these select parameters. Measurements of the detailed flow structure were conducted using particle image velocimetry (PIV) using multiple 16MP cameras to capture a large range of scales that will be expected in these flows, in both a streamwise plane and a cross-section of the wake. This phase was completed in 2016.
For WP2, experiments were conducted in a water tunnel focussing on studying the effect of the roughness patches on scalar dispersion. In order to mount the roughness patches in the water tunnel a new false floor was designed and built, which also concealed a ground-level point source dye injector. Simultaneous measurements of the velocity and scalar field were performed using PIV and planar laser-induced fluorescence (PLIF). The objectives of these experiments were to compare the time-averaged properties of the scalar fluxes with existing models and to investigate how the scalar interacts with the wake of the roughness patch and whether it becomes entrained. This phase was completed in 2017.
So far these results have lead to the following publications, and we plan to continue analysing the rich data resulting from these experiments to produce further outputs:
- Vanderwel, C., Placidi, M., & Ganapathisubramani, B. (2017). Wind resource assessment in heterogeneous terrain. Philosophical Transactions of The Royal Society A: Mathematical, Physical and Engineering Sciences. DOI: 10.1098/rsta.2016.0109
- Vanderwel, C. and Ganapathisubramani, B. (2017). Turbulent boundary layers over multiscale rough patches"", 10th International Symposium on Turbulence and Shear Flow Phenomena TSFP10, Chicago, USA, July 6-9, 2017.
- another in preparation for Boundary-Layer Meteorology"
