Key Takeaways & Executive Findings
- •• • Temperature has negligible effect on rime icing but significantly affects glaze icing region, morphology, and mass; at -1°C, glaze icing thickness at 0.60R (mid-span) exceeds that at 0.90R (tip), a non-monotonic distribution that contradicts conventional monotonic assumptions and necessitates span-wise adaptive de-icing strategies. • • Rime forms streamlined ice while glaze forms horn-shaped ice; as temperature decreases, the glaze icing region shrinks but horn-shaped features become more pronounced, increasing aerodynamic penalties and mechanical loads on blades. • • Maximum icing thickness of rime increases monotonically along blade span, whereas glaze exhibits non-monotonic behavior; this disparity requires distinct icing detection and mitigation protocols for rime vs. glaze conditions in wind farms. • • For identical icing duration, rime icing mass exceeds glaze icing mass; as temperature decreases, glaze icing mass shows a growth trend with decreasing acceleration, implying that at lower temperatures the incremental mass gain per degree drop diminishes, affecting power loss predictions.
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Abstract
This study investigates the icing mechanisms and characteristics of a 300 kW wind turbine at the Xuefeng Mountain Energy Equipment Safety National Observation and Research Station. A full-scale three-dimensional rotating icing model of wind turbine blades is developed using a rotating reference frame and Eulerian gas-liquid two-phase flow model. The differences between rime and glaze icing are compared through numerical simulation in terms of ice morphology, mass, and temperature effects. Results indicate that: (1) temperature has negligible effect on rime icing but significantly affects the icing region, morphology, and mass of glaze icing; (2) rime forms streamlined ice, while glaze forms horn-shaped ice; as temperature decreases, the glaze icing region shrinks but horn-shaped features become more pronounced; (3) the maximum icing thickness of rime increases monotonically along the blade span, whereas glaze exhibits non-monotonic behavior; at temperatures near 0°C (e.g., -1°C), a special case occurs where the icing thickness at mid-span (0.60R) exceeds that at the blade tip (0.90R); (4) for the same icing duration, rime icing mass exceeds glaze icing mass, and as temperature decreases, glaze icing mass shows a growth trend with decreasing acceleration. These findings provide a reliable model and data support for winter wind farm operation and power prediction.
1. Introduction
Wind turbine blades operating in high-humidity cold regions frequently suffer from ice accretion, causing aerodynamic degradation, mechanical overload, and power output losses up to 30–40% in southern Chinese provinces such as Hunan, Guizhou, and Guangxi. Existing research has predominantly relied on two-dimensional airfoil sections, static conditions, or artificial icing experiments, which fail to capture the complex three-dimensional rotating flow and phase-change physics of full-scale blades. This limitation is particularly acute for glaze icing, whose dynamic water film flow and horn-shaped morphology are poorly predicted by current models, leading to uncertain winter maintenance decisions and blind operational strategies.
To address this bottleneck, this study establishes a full-scale three-dimensional rotating icing model for a 300 kW wind turbine using a rotating reference frame and Eulerian gas-liquid two-phase flow approach. The model resolves the distinct formation mechanisms of rime and glaze icing under realistic rotational conditions, enabling accurate simulation of ice morphology and spatial distribution. The results provide a validated numerical framework for winter wind farm operation, power forecasting, and targeted anti-icing design.
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OUYANG Zhan, HUANG Yafei, WANG Jiake, TAN Tian, YANG Xin, YANG Zhongyi (2026). Comparative Study on Rime/Glaze Icing Mechanisms and Characteristics of Wind Turbine Blades Based on Rotating Gas-Liquid Two-Phase Flow. Acta Energiae Solaris Sinica. https://doi.org/10.19912/j.0254-0096.tynxb.202608_9725
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Frequently Asked Questions
What is the primary failure mechanism that distinguishes glaze icing from rime icing under rotating conditions?
Glaze icing forms horn-shaped ice due to dynamic water film flow and latent heat release, whereas rime icing forms streamlined ice from direct droplet freezing. At temperatures near 0°C (e.g., -1°C), glaze icing thickness at 0.60R exceeds that at 0.90R, creating non-monotonic span-wise loads that can induce uneven aerodynamic forces and vibration, potentially leading to blade fatigue failure.
How does temperature affect the icing mass and distribution, and what are the operational thresholds?
Temperature has negligible effect on rime icing but significantly affects glaze icing. As temperature decreases, the glaze icing region shrinks but horn-shaped features become more pronounced. For the same icing duration, rime icing mass exceeds glaze icing mass; as temperature decreases, glaze icing mass increases with decreasing acceleration. At -1°C, the mid-span (0.60R) icing thickness exceeds the tip (0.90R), a critical threshold for de-icing system activation.
What are the scalability bottlenecks for implementing this full-scale rotating icing model in commercial wind farms?
The model requires high-fidelity computational fluid dynamics (CFD) with rotating reference frames and Eulerian two-phase flow, demanding significant computational resources. Grid independence was achieved at 8 million cells with a blade surface mesh size of 28 mm and boundary layer first layer thickness of 1 mm. Scaling to multi-megawatt turbines with larger blades (e.g., >50 m) would require proportionally finer meshes and longer simulation times, potentially limiting real-time forecasting applications.
How does the icing mass growth rate compare between rime and glaze conditions, and what does this imply for power loss prediction?
For identical icing duration, rime icing mass is greater than glaze icing mass. As temperature decreases, glaze icing mass shows a growth trend with decreasing acceleration. This means that at lower temperatures, the incremental mass gain per degree drop diminishes, which must be accounted for in power loss models to avoid overestimating energy deficits during extreme cold events.
What validation metrics confirm the accuracy of the numerical model against experimental data?
The model was validated using lift force as the grid independence criterion, achieving stability at 8 million cells with a 0.43% variation. The numerical domain was a cylinder of radius 1.2R and height 0.4R, with the blade surface mesh size of 28 mm and 5 boundary layers at 1.1 expansion ratio. These parameters ensure capture of complex flow features around the rotating blades, consistent with field observations from the Xuefeng Mountain station.
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