Services

Work Plan and Objectives

Task 46 aims at contributing in several themes related to blade erosion, shortlisted from those introduced by participants during TEM #98, and later. Selection of the final topics was based on the interest expressed by potential participants and technical discussions coordinated by the work package leaders

Objectives and expected results

Climatic conditions driving blade erosion

The science goals are to (i) provide a priori assessments of wind sites regarding the potential for excess
LEE, and (ii) inform wind farm operation to optimize blade lifetimes. The longterm objective is to characterize erosion-relevant properties geospatially / temporally and generate GIS layers (with quality index/uncertainty) for inclusion in a manner similar to the Global Wind Atlas
(https://globalwindatlas.info/)

Wind turbine operations with erosion

This work package has three key overarching objectives: (i) Promote collaborative research to mitigate erosion by means of wind turbine control, assessing the viability of erosion safe mode.
(ii) Improve the understanding of droplet impingement in the context of erosion. (iii) Improve the understanding of wind turbine performance in the context of erosion, specially the effect of LEE surface roughness on aerodynamics

Laboratory testing of erosion

The objective of this work package is to facilitate convergence of laboratory erosion testing practices to achieve a high fidelity test setup representative of the erosion phenomena observed in the field; and reduced uncertainty associated to the preparation of the samples and the testing process and the data analysis.

Erosion mechanics & material properties

The aim is (i) to understand the influence of the material parameters used for leading edge protection on the performance; and (ii) to understand the damage mechanisms and to identify appropriate damage models for accumulative droplet impact erosion attending operational conditions (droplet impact velocity, droplet size, number of impacts per unit surface, etc); and failure modes (surface wear, interface debonding, cracking of underlying layers etc)

Work Packages

Work package 1: Management

The Operating Agents (OAs) support the task, ensuring the timely delivery of scope with the contribution from all partners, using project management practices. The scope includes fulfilling the OAs duties in accordance with the IEA Wind Implementing Agreement and related IEA Wind procedures. The scope includes:
WP1.1 Develop and maintain public website & Task collaborative platform for
participants.
Timeline: Website and data platform delivered in project month Mn#1 (2021/04/15).
Support work continues through the Task 4-year term (Mn#1 – 48).
WP1.2 Technical support to task participants to ensure review & quality of
deliverables (Mn#1 – 48).
WP1.3 External communications (Mn#1 – 48).
WP1.4 Preparation & chair of coordination meetings for all task participants, as
described in Section 6 (Mn#1 – 48).
WP1.5 Preparation & chair of webinars for dissemination, as described in Section 5
(Mn#1 – 48).
WP1.6 Reporting to IEA Wind Executive Committee.

Work package 2: Climatic conditions driving blade erosion

The work package is divided into the following activities:
WP2.1 Definition of priority geographic areas for geospatial mapping of erosion potential.
Compile comprehensive meta-data regarding available hydrometeor data (e.g. rain, hail characteristics and co-availability of wind speeds) for assessing LEE with a particular focus on regions with major wind energy penetration. The deliverables will be a report & spreadsheet summarizing the meta-data. In the report we will document where there are sufficient & sufficient quality data available for parameters of crucial importance to characterizing LEE.

WP2.2 Identification of additional meteorological parameters for erosion.
Compile comprehensive meta-data regarding available data for additional parameters of importance to LEE – specific foci; wind blown dust, UV, occurrence of freezing rain, corrosive agents such as sea spray. The deliverables will be a report & spreadsheet summarizing the meta-data. In the report we will document where there are sufficient & sufficient quality data available for parameters of crucial
importance to characterizing LEE.

Conduct comprehensive literature reviews and synthesize knowledge gained from projects in order to better characterize:
WP2.3 (i) hail, rain & dust climates in target areas
WP2.4 (ii) hydrometeor droplet size distribution as function of climate
WP2.5 Revisit data availability and quality for key meteorological
parameters of relevance to LEE.

WP2.6 Develop a roadmap for a leading-edge erosion atlas including developing recommended report for use of meteorological data for determining Leading Edge Erosion (LEE) classes
WP2.7 Develop report for measurements of LEE drivers including metrology development and prospects for establishing ‘super sites’ for instrument testing and model V&V exercises.
WP2.8 Advance methods to conduct model V&V exercises focused on LEE and improve modeling tools of key atmospheric properties

Throughout the project the WP leaders will liaise with and exchange knowledge with:
• WP3: Wind turbine operation with erosion regarding availability of LEE operational data to refine study regions.
• WP4: Laboratory testing of erosion regarding key parameters of interest of LEE.

Work package 3: Wind turbine operations with erosion

The work package is divided into the following activities:
WP3.1 Model to predict annual energy production loss based on blade erosion class.
Develop a common model of aerodynamic performance loss due to leading edge roughness and erosion standardized classes. Quantification of performance degradation (loss of AEP) as a function of roughness and ‘erosion climate’.
WP3.2 Report on standardization of damage reports based on erosion observations.
Standardization of damage reports for validation of any erosion potential assessment and to allow effective integration of data from operators with laboratory derived estimates.
WP3.3 Droplet impingement model for use in fatigue analysis.
Develop a standard model for droplet impingement, validated with wind tunnel experimental data.
Step 1: Characterization of aerodynamics for droplet impingement probability.
Activity: Develop a standard model for droplet impingement, validated with wind tunnel experimental data.
WP3.4 Potential for erosion safe-mode operation.
Report describing potential for leading edge erosion safe mode operation. This report will be used for seeking participation from industry and research funders towards a coordinated project designed to assess viability and cost-benefit of leading edge erosion safe mode operation.
WP3.5 Accuracy of LEE performance loss model based on field observations (validation). Validation of performance loss model using wind tunnel and field observations. Carry out iterative aerodynamic loss benchmarks with model development and new wind tunnel testing for calibration and validation. Validation of complete performance loss model using probabilistic analysis of field observations. Adapt models to simulate high roughness values (up to P20). Report.

Work package 4: Laboratory testing of erosion

The work package is divided into the following activities:
WP4.1 Available technologies for lab test (report).
Production of a report on technologies available for the laboratory evaluation of erosion. The review aims at covering as much as possible of laboratory testing relevant for wind turbine blade erosion, ranging from formulation and micro-structure over basic physical, chemical and mechanical properties to rain erosion resistance

WP4.2 Erosion failure modes in LE systems (report).
Literature review and partner experience document on failure modes associated to the erosion process. The task is divided in WP4.2a “Failure modes in laboratory testing”, running in parallel with WP4.1 and WP 4.2b “Failure modes on turbines in the field”. The work will be performed in alignment with WP3.2 and WP5.2.

WP4.3 VN data analysis and lifetime tool (report and software). Development of collaborative software on the VN curve analysis for rain erosion testing.

WP4.4 Pre-evaluation of test specimens (report). Development of a recommended report on the pre-evaluation of test specimens.

WP4.5 Test aluminum data analysis, damage accumulation and VN curves (report). Scope is damage accumulation based on slice length, time between intervals and tip speed, data analysis and generation of VN curves on aluminum.

WP4.6 Simple mechanical test for screening of key parameters (report). Laboratory simple mechanical testing and identification of indicative key parameters for pre-evaluation of erosion resistance.

Work package 5: Erosion mechanics & material properties

The work package is divided into the following activities:
WP5.1 Damage models based on fundamental material properties (report)
Identify appropriate damage models for accumulative droplet impact erosion attending specific failure modes based on fundamental material properties. Define appropriate testing methodologies for the material properties defined as input parameters in the modelling.

WP5.2 Multilayer systems (report)
Consider the leading edge as a multilayer system, and the different modelling approaches . Appropriate analysis for Manufacturing issues due to LEP configuration, application procedure, LEP blade integration technology.

WP5.3 Microstructure and macroscopic material properties (report).

Connecting the observed macroscopic mechanical behavior with the polymer
composition and microstructure. Investigating the effect of fillers, additives, polymer composition, on erosion mechanics and accumulation damage. To investigate testing techniques for polymer system analysis linked with the erosion damage progression. Report on the material microstructure and macroscopic material fundamental properties in relation with erosion performance.

Timeline and key dates

Services

Operating Agent Charlotte Bay Hasager

Professor, Department of Wind and Energy Systems

cbha@dtu.dk

DTU Wind and Energy Systems

DTU Wind and Energy Systems
Frederiksborgvej 399
4000 Roskilde
Denmark