Experimental Investigations of an Icing Protection System for UAVs 2019-01-2038
UAV icing is a severe challenge that has only recently shifted into the focus of research. Today, there is a lack of mature mitigation technologies available. We are working on the development of an electro-thermal icing protection technology called D•ICE. As part of the design process, an experimental test campaign at the Cranfield icing wind tunnel has been conducted. This paper describes the icing protection system and shares experimental results on the capability for icing detection and anti-icing. Icing detection is achieved with an algorithm that evaluates temperature signals that are induced on the leading-edge of the wing. A baseline signal is generated during dry (icing cloud off) conditions and compared to a signal during wet (icing cloud on) conditions. Due to significant differences in the heat transfer regime, the system can differentiate between these two states. The experiments show that our system can reliably predict icing conditions based on this principle. Furthermore, the anti-icing capability of the system is proven for two icing cases. The minimum required heat fluxes to keep the surface ice free were obtained by gradually reducing power supply to the heat zones until icing could be detected. The tests include a fully-autonomous run, where the system automatically detected icing and initiated suitable anti-icing measures. To assess the importance of the mitigation system, CFD methods are used to predict the potential aerodynamic performance loss for the test cases. The simulations indicate lift reduction by 15%, drag increase by 25% and significantly earlier onset of stall.
Richard Hann, Kasper Borup, Artur Zolich, Kim Sorensen, Håvard Vestad, Martin Steinert, Tor Johansen
Norwegian University of Science and Technology (NTNU), UBIQ Aerospace
International Conference on Icing of Aircraft, Engines, and Structures