Time Resolved 3D Scanning of Ice Geometries in a Large Climatic Wind Tunnel

In the scope of development or certification processes for the flight under known icing conditions, aircraft have to be tested in icing wind tunnels under relevant conditions. The documentation of these tests has to be performed at a high level of detail. The generated data is used to prove the functionality of the systems, to develop new systems and for scientific purposes, for example the development or validation of numerical tools for ice accretion simulation. One way of documenting the resulting ice geometry is the application of an optical 3D scanning or reconstruction method. This work investigates and reviews optical methods for three-dimensional reconstructions of objects and the application of these methods in ice accretion documentation with respect to their potential of time resolved measurement. Laboratory tests are performed for time-of flight reconstruction of ice geometries and the application of optical photogrammetry with and without multi-light approach. The results of the pre-tests and the review of existing methods are evaluated with respect to scaling of the methods for application in a large icing wind tunnel. As a result of this process, multi-view photogrammetry is used for 3D reconstruction of ice accretion on a common research model wing tip installed in the icing wind tunnel of Rail Tec Arsenal. The results are compared with 3D laser scans of the final ice geometry. The presented approach allows a time resolved quantitative documentation of an icing process without interrupting the experimental ice accretion process.