Oben links (grün): Experimenteller Aufbau in der Klimakammer mit Rotorblattabschnitt, Infrarotkamera und den wesentlichen Eingangsgrößen. Oben rechts (blau): COMSOL-FEM-Modell mit geometrischem Blattmodell und Randbedingungen (Temperaturtransienten, Materialeigenschaften). Unten: Gegenüberstellung von gemessenem Thermogramm (links) und FEM-Simulation (rechts) nach 85 Minuten Aufheizung mit 2 K/h; der Doppelpfeil kennzeichnet den qualitativen Vergleich beider Datensätze.
Source: BAM
Wind energy plays a central role in the global energy transition, but the rapidly growing fleet of turbines also creates an urgent need for reliable inspection methods for rotor blades. Blades are complex composite structures, and detecting internal damage or structural defects without dismantling them is technically challenging.
Passive infrared thermography is a promising approach: it exploits natural temperature fluctuations – such as day-night cycles or weather changes – to reveal differences in how different materials heat up and cool down. This can make hidden structural features or defects visible at the surface, without any artificial heat source. Researchers at BAM investigated a section of a decommissioned wind turbine blade in a climate chamber. The blade section was subjected to controlled heating and cooling cycles while an infrared camera continuously recorded its surface temperatures. At the same time, the experiment was reproduced using a finite element model (FEM) built in COMSOL Multiphysics, based on the known geometry and material properties of the blade. The climate chamber provided a fully controlled environment for the first time, free from the influence of solar radiation, wind, and other uncontrollable outdoor variables.
The comparison shows that the simulation model correctly describes both the surface temperature evolution and the appearance and disappearance of thermal contrasts at structural features such as the leading-edge bonding. Small remaining differences were traced to temperature inhomogeneities within the climate chamber and a temperature-dependent calibration sensitivity of the infrared camera.
The study demonstrates for the first time that thermographic inspection of wind turbine blades is feasible even without sunlight—provided that the air temperature changes relatively uniformly by at least 1°C over the course of an hour. The validated model serves as the basis for future simulations under realistic outdoor conditions, including sunlight, cloudy or clear skies, and wind.
Modeling Temperature Responses of a Wind Turbine Blade Section Under Climate Chamber Conditions – Part 1: Challenges for FEM Simulations.
Chaudhuri, S., Krankenhagen, R., Lapšanská, I., & Stamm, M.
Wind Energy, 2026