Development of electro-mechanical ice protection systems for small aircraft

Abstract

The need for sustainable, all-weather capable and highly available aircraft, like small commuter aircraft, UAVs and rescue helicopters, lead to an increased relevance of the issueof in-flight icing and more energy efficient ice protection systems (IPS). Especially small aircraft, flying at low altitude, experience a high risk of in-flight icing. Without IPS, the aircraft must be navigated around the area with icing condition, which leads to additional flight times and increased energy consumption and therefore might result to an unsuccessful flight mission. Due to their limited margins in terms of energy capacity and weight, IPS for small aircrafts must be energy efficient and lightweight. Electro-mechanical de-icing systems are a promising technology in terms of low energy consumption and low weight. Piezoelectric actuators, integrated into the aircraft’s structure, excite the iced components and mechanically remove the accreted ice-layers in designated areas, like wings, air intakes or rotor blades. Low frequency excitation of the component’s resonance modes leads to large deformations and induce cracks and delamination of the ice layer. However, the effective removal of these ice layers from realistic aircraft structures is challenging, since the ice layer’s geometry and mechanical properties vary strongly for different icing conditions. Additional challenge is the integration and excitation of the piezoceramic actuators, which must be properly designed according to the structure’s specific dynamic behavior. In a current research project, this technology is being developed and tested on an electrically driven ducted fan propeller. This off-the-shelf propulsion system is used to demonstrate the feasibility of this technology on realistic non-rotating parts, such as the Nacelle, as well as on rotating parts, like the propeller blades. The research work includes detailed numerical analysis of the integrated piezoelectric de-icing system and ice detection sensors. For validation of the numerical results, the de-icing capability as well as the demonstrator’s icing behavior will be tested in the DLR’s whirl tower under realistic icing conditions.