Floating wind turbines that move at the right frequency can actually speed up their own wake recovery, new simulations reveal
Offshore wind turbines don’t just spin — they also surge, sway, pitch, roll, and yaw as waves push against their floating platforms. Engineers have generally assumed that all this movement disrupts the airflow behind a turbine, slowing wake recovery and reducing power output for turbines downstream.
A new simulation study challenges that assumption. Researchers ran high-fidelity large-eddy simulations across five distinct types of floating motion and tracked what happened to each turbine’s wake — the turbulent corridor of slower air trailing behind the rotor. The frequency of movement, not its amplitude, turned out to be the decisive factor.
Why floating turbine motion matters for wind farms
By September 2024, Europe had 35 gigawatts of installed offshore wind capacity, most of it from fixed-bottom turbines anchored in relatively shallow water. As the industry pushes into sites deeper than 60 meters — where fixed foundations become impractical — floating platforms are increasingly essential.
This exception shows that the right frequency alone isn’t sufficient — the direction of motion determines whether the resulting flow structures help or hurt.
In any wind farm, upstream turbines cast a wake: a corridor of slower, more turbulent air that reduces energy output for turbines behind them. Floating platforms move in up to six directions simultaneously, constantly perturbing airflow in ways fixed turbines never do. Standard engineering wake models weren’t built for this, and closing that gap was a central motivation for this study.
How the simulations were set up
The researchers used large-eddy simulations coupled with an actuator-line model to replicate a scaled version of the DTU 10 MW wind turbine inside the Politecnico di Milano wind tunnel. Five degrees of freedom were tested: surge, sway, roll, pitch, and yaw. Heave was excluded.
For each motion type, two scenarios were compared — low frequency with large amplitude, and high frequency with small amplitude — to isolate whether frequency or amplitude drives wake behavior. A key methodological innovation was the use of circular “radial probes” sampling full two-dimensional cross-sections of the wake at multiple downstream positions, capturing more spatial structure than the simpler linear probes used in most prior studies.
Frequency beats amplitude: the key finding
The most striking result was how little the size of platform movement mattered. Low-frequency, high-amplitude motions — where the turbine moved up to ten times farther — produced wakes nearly identical to a stationary fixed-bottom turbine.
High-frequency, low-amplitude motions told a different story. Despite much smaller physical displacement, these cases triggered amplified perturbations, earlier breakdown of tip vortices, sharper turbulence peaks, and measurably faster wake recovery. The explanation lies in resonance: high-frequency motions fell within the natural energy range the wake develops on its own, exciting modes the flow was already primed to amplify. Even tiny oscillations at the right frequency can meaningfully reshape downstream airflow.
Cross-stream motion recovers wakes faster — with one notable exception
Among high-frequency cases, the direction of motion also mattered. Sideways motions — sway and roll — produced the greatest wake recovery benefits, while motions combining cross-stream and streamwise components, such as pitch and yaw, ranked in the middle. Purely streamwise surge ranked last.
Sway and roll generate lateral meandering that boosts momentum mixing more effectively than the pulsating structures surge creates. The high-frequency surge case was the only one that hampered wake recovery compared to a fixed turbine, creating large low-velocity pockets inside the wake. This exception shows that the right frequency alone isn’t sufficient — the direction of motion determines whether the resulting flow structures help or hurt.
Wind tunnel constraints and what they mean for real-world conditions
The Politecnico di Milano wind tunnel has a blockage ratio of roughly 8.46 percent and an asymmetric cross-section, introducing confinement effects including earlier tip-vortex mergers in the vertical direction. Despite these limitations, the fundamental phenomena — frequency-dependent recovery, turbulence intensity changes, and vortex trail dynamics — remained consistent with results from full-scale simulations and other experiments in the literature.
One important caveat involves the idealized inflow. Laminar conditions and constant rotor speed were used to isolate motion effects. In reality, even modest turbulence intensity — around 1.5 percent — can dampen the coherent structures that floating motion creates, and prior work suggests that under realistic stochastic sea states, wake recovery benefits may be reduced or absent entirely.
Implications for floating wind farm design
The results point toward an underappreciated design variable: platform motion frequency. Current wake engineering models treat floating turbine motion largely as a source of disruption, without accounting for how frequency shapes downstream flow. This study suggests frequency belongs alongside amplitude as a first-class parameter in next-generation models.
Cross-stream platform motions could also inform layout decisions. If sway and roll consistently accelerate wake recovery, designers might factor motion characteristics into inter-turbine spacing choices. Future work should incorporate turbulent inflows, active blade pitch and rotor speed control, and multi-degree-of-freedom motions driven by actual sea states. Whether the frequency-selectivity observed here survives into real-world conditions is the question the field now needs to answer.
Reference: Amaral, R., Houtin-Mongrolle, F., von Terzi, D., Laugesen, K., Deglaire, P., and Viré, A.: Dynamics of floating-wind-turbine wakes in a wind tunnel setup, Wind Energ. Sci., 11, 3401–3426, https://doi.org/10.5194/wes-11-3401-2026, 2026.
Daniel García is an Editor-in-Chief with strong expertise in structural work and engineering principles. He combines this technical foundation with deep knowledge of energy, spatial design, and emerging technologies, bringing a forward-thinking and analytical approach to editorial leadership.
