Reynolds-number and surface-modeling sensitivities for experimental simulation of flow over complex topography

This paper documents the development of an experimental approach for determining the wind characteristics over complex topography. Using fast-response pressure probes, vertical wind profiles were measured over wind-tunnel models representing the complex topography of a wind farm currently under construction. A terraced-model approach was taken to simplify the manufacturing of the topographic models, providing the added benefit of enhanced surface roughness from the terraced steps. A preliminary study in a small wind tunnel identified restrictions on the Reynolds number and terrace step size that are required for attaining adequate high-Reynolds-number boundary-layer characteristics at a scale of 1:1500. Subsequent measurements over the entire wind-farm topography were compared to site measurements from meteorological masts, from which recommendations for improved experimental simulation techniques are identified.

► Wind tunnel modelling of flow over complex topography.
► Method provides correct aerodynamic scaling to reproduce high-Reynolds-number flow characteristics.
► Efficient model fabrication technique provides beneficial surface roughness.
► Reasonable agreement between wind tunnel and site measurements.
► Recommendations for improved simulation through modified boundary conditions.