The Power Curve solution revolves around vortex generator technology. When installed correctly, vortex generators increase aerodynamic lift and turbine power production.

Power Curve vortex generators improve turbine AEP by solving two generic problems with blade aerodynamics.

On the inner part of the blade, Power Curve VG panels are designed to improve the poor aerodynamic qualities that are intrinsic to thick airfoils.

On the outer part of the blade, Power Curve VG panels are designed to mitigate declining aerodynamic qualities caused by surface erosion.

The inner part of the blade

Video: Vortex generators on the inner part of the blade

The outer part of the blade

Video: Vortex generators on the outer part of the blade

Aerodynamic problems explained

For a wind turbine to produce energy, the wind must be able make the rotor turn by flowing cleanly around the blades. The longer the airflow stays attached to the blade, the more lift force and therefore energy is generated.

If the airflow separates from the blade surface, turbulence occurs along the trailing edge. This is called ‘aerodynamic stall’ and results in decreased lift, as illustrated in the videos above. The more airflow separation, the further the stall point moves towards the leading edge, and the less lift force is generated.

This is why the majority of the blade is shaped like an aircraft wing. These thin airfoils are aerodynamically optimal and facilitate the best possible lift and energy production.

The inner part of the blade: Thick airfoils

The inner part of nearly all turbine blades is characterized by thick airfoils. This is a necessary production compromise, as shapes must transition from thin airfoils to a circular geometry at the root, where the blade is attached to the turbine hub.

The result is suboptimal aerodynamic properties – in other words, the airflow in this area is unable to stick to the blade for as long as desired. Instead, the airflow separates from the blade surface, or ‘stalls’, resulting in suboptimal energy production.

The outer part of the blade: Leading Edge Roughness

The outer part of the blade is designed for optimal aerodynamic performance. But this part of the blade travels at very high speeds (200-300 km/h), meaning that rain, hail, bugs, sand and other particles inevitably erode or cling to the blade surface over time.

The blade surface will gradually degrade as the wear and tear takes its toll, ultimately causing erosion along the leading edge. As a result, the aerodynamic properties of the blade are jeopardized, and power production declines.

How Power Curve vortex generators help

Our vortex generator technology mitigates both of these problems.

Issues with thick airfoils on the inner part of the blade have long been known, but surface erosion on the outer part, or ‘Leading Edge Roughness’, has previously been impossible to quantify and characterize to a sufficient degree. But at Power Curve, we have cracked the code.

When designed correctly for a given turbine and properly installed, Power Curve vortex generators can postpone the stall point on both the inner and the outer part of the blade. The end result is that lift forces are reinstalled, helping our clients improve their turbine AEP performance.

Power Curve vortex generators have a triangular fin with a sharp leading edge. They are fabricated in pairs and integrated on baseplates, suitable for accurate and fast adhesive attachment on the blade surface.

Each pair is symmetrically opposed and generates counter-rotating and interacting vortexes. This deliberate disturbance flushes energy from the higher boundary layers into the lower and weakened boundary layer, making it possible for the airflow to stay attached for a longer distance along the blade surface.