Niche in the market for a means of adapting older wind turbine blades to improve efficiency, increase their operational envelope (making more sites economic to use) and obtaining greater yields from assets already installed.
The solution proposed by our client was to fit a winglet (tip) to the blades. This requires accurate tip geometry, so that an aerodynamic study can be performed, allowing efficiency gains to be calculated.
AES Requirement: What?
The brief we were given was to travel to the storage facility, capture the detail of the last 3m of the tip of a blade, process the scans, and loft a clean CAD surface through the scan data. This CAD surface was to be used directly in our client’s CFD software to create the benchmark of the existing blade for the aerodynamic study. The generated CAD surface was compared against the original scan data to highlight any deviations.
These requirements were well suited to our portable scanners and flexible approach, waiting for a weather window before travelling to the site and performing the scan.
Uses: Why capture geometry?
Scanning objects and obtaining their surfaces allows several other activities to be considered such as;
- Comparison to the original design data, which has several benefits itself: quality checking, periodic maintenance checks, condition monitoring over time,
- Manufacturing data: establish a baseline for quality inspection, determining tolerances of the finished part and assembly process, capture of ‘as-built’ component
- Modification and Reverse Engineering of part: Design of interfacing mould surfaces, part modification/optimisation, input into CFD or FE Analysis tools.
- Using scanned data eliminates on-site templating and allows remote design/analysis of modifications to the part, as well as checking the accuracy of parts before and after delivery to site.
AES Method: How?
Preparation prior to arriving on-site was key to maximising the time scanning in the favourable weather window, and the portability and simplicity of the allowed the scan to be completed in a day.
Photographs of the object and site conditions are taken before and after the scan for record and part identification purposes. The parts are then prepared for scanning (if necessary) and the data captured.
Post processing on test scans is performed to check settings are optimised to ensure scan accruacy given the object’s texture, reflectivity, colour and lighting, then scanning commences.
Post processing and data manipulation and lofting the surfaces (as required in this instance by our client) are typically done at our facilities, and then verified using CAD to scan comparisons.
Providing our client with the original scan data, our lofted tip CAD surface, and the comparison between the two, enabled them to perform their aerodynamic study – and evaluate the benefits of their proposal versus the baseline (scanned) blade.
Scanning the blades in this manner means that should the project proceed beyond a feasibility study to the design and manufacture of a tip extension, the necessary data already exists and no further site visits are required to capture the geometry, saving time and costs.