Streamwise Scalings of the Turbulent Wake Generated by a Scaled Wind Turbine Under Laminar and Turbulent Background Flows

We report an experimental study on the turbulent wake generated by a scaled wind turbine in a wind tunnel. Hot-wire anemometry is used to characterise the far wake under laminar and turbulent background flows up to 32 rotor diameters downstream the generator. We focus on the streamwise scalings of the centreline mean velocity deficit and the wake width. Following the Townsend-George theory, we verify that both parameters are properly modelled by power laws with the streamwise distance. As the exponents of the power laws are known to depend on the turbulent kinetic energy dissipation scalings, we systematically study the streamwise scalings of the three parameters (centreline mean velocity deficit, wake width, and dissipation), finding that our results are consistent with the standard Richardson-Kolmogorov energy cascade.