wind tunnel simulation of wake effects on wind turbine performance

M. S. Adaramola and P-Å KrogstadM. S. Adaramola and P-Å KrogstadDepartment of Energy and Process Engineering,

The Norwegian University of Science and Technology, N-7491 Trondheim, Norway

IntroductionObjectivesExperimental set-upResultsConclusions

Turbine wake

Turbine wakeWind conditions

Turbine wakeWind conditions

Performance characteristics

Turbine wakeWind conditions

Performance characteristics

Site topology/surface roughness

Turbine wakeWind conditions

Performance characteristics

Site topology/surface roughness

Downstream turbine performance depends on these parameters as well as distance from the upstream turbine.

1.Effect of distance of separation between the turbines, S/D.

1.Effect of distance of separation between the turbines, S/D.

2.Effect of power extracted from the upstream

turbine, i.e. function of tip speed ratio,

1.Effect of distance of separation between the turbines, S/D.

2.Effect of power extracted from the upstream

turbine, i.e. function of tip speed ratio,

3.Effect of downstream turbine pitch angle, β.

Wind tunnel Dimensions:

•Height – 1.9 m•Width – 2.7 m•Length – 12 m

Blockage ratio: 12.4%

Wind velocity: 11.5 m/s

Gap between turbines:

S/D = 3, 6, 9

Downstream turbine:

β = -2o, 0o, 2o

Upstream turbine operating conditions:

• Optimum • Low, optimum and high

Model turbine layout

Effect of S/D on CP curve for downstream turbine

Relative max. Cp when downstream turbine blade pitch setting is β = 2o

Effect of downstream turbine blade pitch setting (β ) for S/D = 3

Cp as function of upstream turbine

Relative max. Cp as function of upstream turbine Downstream turbine at S/D = 3

1. The turbines should be operated at different blade

pitch angles.

1. The turbines should be operated at different blade

pitch angles.

2. Operating the upstream turbine slightly outside its

optimum will increase the performance of the

turbines further downstream.

1. The turbines should be operated at different blade

pitch angles.

2. Operating the upstream turbine slightly outside its

optimum will increase the performance of the

turbines further downstream.

3. Increase in the downstream turbine power production

may improve the overall wind farm performance.

THANK YOU