Articles | Volume 1, issue 2
Wind Energ. Sci., 1, 237–254, 2016
https://doi.org/10.5194/wes-1-237-2016
Wind Energ. Sci., 1, 237–254, 2016
https://doi.org/10.5194/wes-1-237-2016

Research article 17 Nov 2016

Research article | 17 Nov 2016

Effect of Reynolds number and inflow parameters on mean and turbulent flow over complex topography

Ryan Kilpatrick1,3, Horia Hangan1,2, Kamran Siddiqui1,3, Dan Parvu1,2, Julia Lange4, Jakob Mann4, and Jacob Berg4 Ryan Kilpatrick et al.
  • 1WindEEE Research Institute, University of Western Ontario, London, Ontario, N6M 0E2, Canada
  • 2Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario, N6A 5B9, Canada
  • 3Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, N6A 5B9, Canada
  • 4DTU Wind Energy, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde, Denmark

Abstract. A characterization of mean and turbulent flow behaviour over complex topography was conducted using a large-scale (1 : 25) model in the WindEEE Dome at Western University. The specific topographic feature considered was the Bolund Hill escarpment facing westerly winds. A total of eight unique inflow conditions were tested in order to isolate the impact of key parameters such as Reynolds number, inflow shear profile, and effective roughness, on flow behaviour over the escarpment.

The results show that the mean flow behaviour was generally not affected by the Reynolds number; however, a slight increase in speed-up over the escarpment was observed for cases with lower inflow roughness. The shape of the inflow wind shear profile also had a minor impact on the mean flow near the escarpment. More significant effects were observed in the turbulent flow behaviour, where the turbulent kinetic energy (TKE) over the escarpment was found be a strong function of inflow roughness and a weak function of the Reynolds number. The local change in the inflow wind shear was found to have the most significant influence on the TKE magnitude, which more closely approximated the full-scale TKE data, a result which had not been previously observed in wind tunnel modelling of this topography.

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Short summary
This paper contributes to the scientific knowledge of flow behaviour over complex topography by extending the physical modelling work of the flow over the Bolund Hill escarpment, a test case for the validation of numerical models in complex terrain for wind resource assessment. The influence of inflow conditions on the flow over the topography has been examined in detail using a large-scale topographic model at high resolution at the unique WindEEE dome wind research facility.