Projects

This project was funded by the Centre for the Development for Industrial Technology (CDTI, Spanish Government). The project was focused on research and development of a technology for the development of advanced coating systems used for protecting wind turbine blades and reducing significantly manufacturing and maintenance costs.

LEP4BLADES Project aims to contribute definitely to solve one of the most important challenges which currently the wind rotor blade manufacturing sector is facing, such as the protection of the leading edge of the blades, due to the progressive increase in the size of wind turbines, this is a key factor, so it is important to extend the blade´s operating life in order to avoid maintenance operations due to erosion and other environmental factors, the project focuses on the industrial scale-up of this leading edge protection innovative AEROX´s technology. 

With the gradual increase in the size of wind turbine blades, Leading Edge Protection of the blade has become one of the most important challenges that lie ahead wind industry. Funded by the Centre for the Development of Industrial Technology (CDTI, Spanish Government), this project is focused on research and development of a novel hybrid polymer technology, AEROX AHP LEP for the development of advanced coating systems used for the leading edge protection of wind turbine blades

The material characterization and measurement of fibre preform permeability and resin cure kinetics is one of the main issues in liquid composite processing since it plays a key role in process design and control. It allows predicting the flow behaviour in porous media with numerical simulation. The appropriate material modelling is a critical input parameter needed by simulation. In spite of using accurate computer simulations, the modeling and characterization of the materials is usually a tedious and extensively work in industry. The appropriate computational resolution of the flow kinematics during filling allows one to relate the local material properties such textile permeability and resin viscosity with the flow motion under dynamic behaviour.

In this work, a mixed numerical/experimental technique based on artificial vision is used for estimating the induced effect of the surface coating curing in the laminate impregnation and the flow front advance during filling under controlled conditions. The procedure computes local material parameters and is proposed based on the aim of matching the empirical data with the simulation. For that purpose, the method iterates the value of permeability and induced viscosity in the simulation until it matches the evolution of the experimentally measured flow front.

That approach can be used to obtain an analytical demonstration of the correct convergence of the method in 1D. Finally, different tests with empirical and simulated data have been shown. These tests show the ability of the algorithm to detect different surface coatings.

In particular, excellent results have been obtained in the project “AEI-010500-2015-373 Design , validation and manufacture of a prototype equipment to test and check a new polycarbonatediol-polyurethane based coating to protect the leading edge of wind turbine blades”, founded by MINECO (Ministerio de Industria, Energía y Turismo) It is focused into the optimization guidelines for coatings developed and validated using both laboratory techniques and rain erosion testing. Moreover, the appropriate development of numerical rain erosion damage prediction models yielded a tool for effective leading edge coating design.

The erosion of wind turbine blade leading edges has seen a dramatic increase in both the frequency of occurrence and the rate at which leading edges are eroding. The costs associated with erosion in terms of loss of power output and repair and downtime is significant and has a large impact on the LCoE (Levelized Cost of Energy) for wind. Solutions need to be developed to mitigate this problem, and the blade surface coating design is regarded as a key issue for the wind energy industry. 

Resin Infusion (RI) is increasingly used in wind energy systems where low weight and high mechanical performance materials are demanded. The in-mould coating plays a key role in the manufacturing and performance of Wind Turbine Blades. The coating is usually painted or sprayed onto the mould tool before the dry preform is inserted, adequate adhesion in the coat-laminate interphase and good surface finish is often required for mechanical performance or durability reasons. 

Erosion damage, caused by repeated rain droplet impact on the leading edges of wind turbine blades, is a major cause for concern. In the current work, an investigation (among others) has been conducted into the curing of the coating. Test results are presented and discussed to relate the in-mould curing of the coating on the interphase coat-laminate mechanical properties and on the resulting rain erosion durability of the component. A mixed numerical/experimental technique based on artificial vision was used to estimate the induced effect of the surface coating curing in the laminate impregnation and the flow front advance during filling under controlled conditions. The experimental investigation focused on the effects of the curing of the coating on important mechanical performance parameters, which were assessed by pull-off testing, peeling-adhesion testing and rain erosion testing. A post-mould solution has been also investigated. It is based on avnovel hybrid polyurethane-urea technology. It is also outlined the necessity of matching the developed LEP coating properties to the blade structure of the fabric and hence its relation with the laminate as an integral solution. 

The rain erosion testing indicated that samples manufactured with a higher degree of cure (as determined using DSC), performed worse in regard to erosion compared to those that had a lower degree of cure. These results correlate with the peeling tests where the moulded coating had a lower value of the force of failure for interphase adhesion testing. Moreover, the determination of coating factors that affect erosion performance are also investigated. It was accomplished by evaluating various aspects of the system, these include; vibro-acoustic and mechanical characterization, coating application method and curing, adhesion to substrate, coating film thickness and the effect of coating defects on the erosion degradation process. Optimization guidelines for coatings were then developed and confirmed using both laboratory techniques and rain erosion testing. Moreover, the appropriate development of numerical rain erosion damage prediction models could yield a tool for effective leading edge coating design. The erosion damage is affected by the repetitive shock wave caused by the collapsing water droplet on impact, and the elastic and viscoelastic mechanical response of coating and the blade structure, and the interactions between them. The understanding of these interactions through the numerical modelling is limited but thought to be of key significance and allow one to optimise manufacturing and coating process for blades into a knowledge-based guidance.

Aerox currently participates as a partner in the DEMOWIND 2 ERA-NET COFUND ACTION JOINT CALL 2016: Delivering Cost Reduction in Offshore Wind. The consortium consists of different companies and European institutions ORE Catapult, CENER , BLADENA, TotalWind Blades, DTU, DIS, TNO, Gamesa, and CEU. 

“Offshore Demonstration Blade” Project aims to validate the consortium companies developments in real environmental and operational conditions.

This project aim is to reduce the Cost of Energy of offshore wind.