We proposed to accompany the SFWA-BLADE flight test phase with adequate wing surface metrology, to measure profile, waviness, steps, gaps, 3D disturbances, and surface roughness. The envisaged metrology system already exists and its performance to the specifications stipulated in the call had been demonstrated on relevant reference artefacts. So far, we have successfully used it for on-site BLADE wing tooling measurements, demonstrating portability besides the uncertainty required.
The measurement system was a fringe-projection system, custom built for the specific requirements of wing metrology. It can e.g. easily detect waviness of 0.1 mm and its noise limit is about 10 micrometres. The nominal field of view was 1280x800 mm², making it perfectly suited for measurements in inter-rib spaces of the BLADE wings. It can be adjusted to any orientation desired, and its position can be registered with laser tracker assistance. This made it possible to locate unconnected surface segments correctly in 3-D space, thus eliminating the need for large overlaps between surface sub-areas. However, we have also shown that very good results are achievable without laser tracker assistance by ""stitching"" of sub-areas together into one combined data set for the entire wing tip surface of 9x2 m².
The applicants have decades of experience in full-field non-contact optical metrology, including three years of collaboration within the current BLADE consortium under call JTI-CS-2010-05-SFWA-03-004. The business infrastructure for a successful effort was already in place, as are evaluation methods which were further refined during the current call and had reached a high degree of maturity by the scheduled start time of the flight test metrology campaign.
According to the Air Transport Action Group (ATAG), aviation is responsible for 12% of CO2 emissions from all transport sources and accounts for around 2% of all humanly-generated CO2 emissions. As the aviation industry thrives and passenger traffic doubles over the next twenty years, it's incumbent upon the aeronautical community to take responsibility by creating and cultivating powerful technologies that are environmentally benign.
Within the CleanSky programme, SFWA ITD carried out the ‘BLADE’ - Breakthrough Laminar Aircraft Demonstrator in Europe, under management of Airbus. This demonstrator was being developed to build wings for passenger planes that allow a natural laminar flow under cruise conditions. This helped reduce fuel consumption and emissions caused by air travel.
Numerous technological challenges must be overcome to build wings that comply with the necessary tight aerodynamic tolerances for profile waviness and roughness, required to enable a natural laminar flow. Also, the precision manufacturing and assembly must necessarily be accompanied by high precision metrology on scales from meters to sub-millimeters. No measurement system exists which was capable of measuring large areas with high lateral and depth resolution.
The WiMo / WimCAM projects aimed at the development and testing of a strategy to combine different measurement systems to a single one which allows for measuring large areas with the necessary resolution. In addition, new strategies for handling the huge amount of data and evaluate them were developed. The projects results therefore fulfilled the requirements of a quality control in a production line for the natural laminar flow wing.