Icing tests to determine the collection efficiency of test objects in the FH JOANNEUM IWT (Icing Wind Tunnel)

One focus for further development of icing possibilities for analyses in the Vienna Climatic Wind Tunnel is on the target group of multicopter and drones. In this context, liquid water content calibration is essential prior to test execution. To ensure accuracy, the collection efficiency must be known for the exact dimensions of the test object via the corresponding velocities and particle sizes. To determine this basic data for low velocities, experimental icing tests were carried out in the FH JOANNEUM IWT (Icing Wind Tunnel) on various test objects (wing segments & icing blade) and a method for the numerical and experimental determination of the “Collection Efficiency” was tested. The work is carried out by RTA and a master student of FH JOANNEUM, in cooperation with the research project JOICE (“Joint Austrian In-flight Icing Research Venture 2020+”) as part of the “Austrian aviation programme TAKE OFF” funded by the Federal Ministry for Transport, Innovation and Technology.

The tests were carried out successfully. Some potential improvements were identified in the test set-up and the test procedure; these are described in more detail in the student’s dissertation. A correlation between the collection efficiency and the brightness of the ice accumulation on the icing blade as well as on the wing profile could be determined. The experimental results showed similar collection efficiency patterns as the numerical calculations. In the afternoons, the limit of the FHJ wind tunnel was partially reached and the low temperatures could no longer be kept stable at higher speeds. As further investigations are necessary with regard to the collection efficiency, there will be no additional publications on this for the time being, but it is planned to pursue this topic further in a future Master thesis.