NKK Boundary Layer Wind Tunnel Facilities

Atmospheric Boundary Layer Wind Tunnel Applications in Wind Turbine Siting

Atmospheric boundary layer wind tunnels (ABLWTs) have been used for 40 years to simulate the interaction of the wind and earth in the lowest few hundred meters of the atmosphere. ABLWTs are well-suited for investigating flow in complex terrain and have different strengths and weaknesses than numerical modeling. There are a wide variety of applications, including performing wind resource assessm...

Tailoring wind properties by various passive roughness elements in a boundary-layer wind tunnel

Boundary-layer wind tunnel provides a unique platform to reproduce urban, suburban and rural atmospheric boundary layer (ABL) by using roughness devices such as vortex generators, floor roughness, barrier walls, and slots in the extended test-section floor in the contraction cone. Each passive device impacts wind properties in a certain way. In this study, influence of various passive devices o...

Wind Tunnel Tests on Horn-Shaped Membrane Roof Under the Turbulent Boundary Layer

Turbulence Spectra and Dissipation Rates in a Wind Tunnel Model of the Atmospheric Convective Boundary Layer

A model of the atmospheric convective boundary layer (CBL) is realized in the thermally stratified wind tunnel of the Institute of Hydrology and Water Resources, University of Karlsruhe. Further experimental results from this model are presented. The wind tunnel with a test section 10 m long, 1.5 m wide, and 1.5 m high allows one to generate a quasi-stationary, horizontally evolving CBL, charac...

A Wind-Tunnel Simulation of the Wake of a Large Wind Turbine in a Weakly Unstable Boundary Layer

Measurements have been made in the wake of a model wind turbine in both a weakly unstable and a baseline neutral atmospheric boundary layer, in the EnFlo stratified-flow wind tunnel, between 0.5 and 10 rotor diameters from the turbine, as part of an investigation of wakes in offshore winds. In the unstable case the velocity deficit decreases more rapidly than in the neutral case, largely becaus...