HAWT Model Testing in a Compressed Air Wind Tunnel

The increasing size of wind turbines presents difficulties for gathering experimental data due to the high Reynolds numbers that are unachievable in conventional wind tunnels. These wind turbines will often rely on field experiments which lack the ability to provide consistent control conditions. Penn State's Compressed Air Wind Tunnel (CAWT) can test scaled models at Reynolds numbers on the same order of magnitude as full scale by increasing the air pressure inside of the wind tunnel up to 500 psi. Ongoing work at Penn State is focused on the design of a horizontal axis wind turbine (HAWT) testing stand that can use a 10 in model to match the Reynolds number of a 10 m diameter turbine of up to 8.7 million based on rotor diameter. The presented work will include an operation map showing the range of achievable Reynolds numbers at different velocities and pressures, a structural analysis of the setup at maximum operating conditions, and preliminary results in the CAWT using a model based on the NREL Unsteady Aerodynamics Experiment Phase VI at full dynamic similarity.