Ultrasonic ice protection systems

Protection systems against ice on leading edge conventionally use thermal and pneumatic solutions. In case of thermal solutions with piccolo tubes (the most usual technology), the hot air is extracted from engine, which decrease its efficiency. The trend is to move to all electric deicing systems. Electro-thermal solutions have been implemented but at the cost of a high energy consumption. This work focuses on low-consumption electromechanical deicing solutions based on piezoelectric transducers. After a review of deicing systems, the main features of electromechanical de-icing devices are identified and piezoelectric ceramic-based deicing systems are studied. Numerical simulations allow computing the configurations that lead to low-consumption, compact ultrasonic deicing devices. First tests of piezoelectric de-icing systems are performed on simple cases such as plates. These tests are promising and allow analyzing the key design drivers (the frequency range to use, the impact of the ice thickness on the system performance) for the design of such systems. First results on the voltage and the consumed current of such devices are also given

Comparison of extensional and flexural modes for the design of piezoelectric ice protection systems

Many researches focus on piezoelectric ice protection systems with the objectives to develop light and low consumption electromechanical systems for de-icing. These systems use vibrations, generated by the excitation of flexural, extensional or coupled resonance modes, to produce tensile stresses in the ice or shear stresses at the interface ice/support in order to remove ice. The objectives of this work are to analyse flexural and extensional resonance modes according to important design drivers for this type of systems: resonance frequency range, generation of tensile and shear stresses, electromechanical coupling factor, damping and fracture propagation. A final comparison gives pro and cons of each mode type for each design drivers for helping the designer of piezoelectric ice protection systems

Evaluation Of Anti-Icing Polymer Coatings

Ice accumulation on aircraft, wind turbines and power lines can have detrimental effects, including efficiency reduction, mechanical failures and the creation of safety hazards. The aim of this study is to investigate the ice adhesion and wear resistance of three hydrophobic and icephobic coatings applied onto an aluminum substrate. Ethylene-tetrafluoroethylene (ETFE) coating was deposited using a plasma spray method while advanced liquid glass (ALG) and silicone R-2180 were both applied using dipping followed by furnace curing. Water was applied and frozen between both bare and coated surfaces using a custom built jig at -20 °C for 24 hours. The ice adhesion strength was measured using a lap shear test done inside an insulated chamber. The results showed low ice adhesion strengths for both ALG and silicone R-2180 coatings when compared to the bare surface. It was also found the silicone R-2180 coating had a higher wear rate than both the ETFE and ALG coatings. By combining icephobic coatings with an ultrasonic de-icing system, the power required by the system can be reduced, creating a low-powered active approach to the de-icing problem

Electro-mechanical Resonant Ice Protection Systems: Analysis of Fracture Propagation Mechanisms

Recent research is showing growing interest in low-power electromechanical de-icing systems and, in particular, de-icing systems based on piezoelectric actuators. These systems use the vibrations generated by piezoelectric actuators at resonance frequencies to produce shear stress at the interface between the ice and the support or to produce tensile stress in the ice. This paper provides analytical and numerical models enabling a better understanding of the main de-icing mechanisms of resonant actuation systems. Different possible ice shedding mechanisms involving cohesive and adhesive fractures are analyzed with an approach combining modal, stress and crack propagation analyses. Simple analytical models are proposed to better understand the effects on ice shedding of the type of mode, ice thickness, or frequency with respect to cohesive and adhesive fractures

Electro-mechanical Resonant Ice Protection Systems: Initiation of Fractures with Piezoelectric Actuators

Recent research is showing growing interest in low-power electromechanical de-icing systems and, in particular, de-icing systems based on piezoelectric actuators. These systems use the vibrations generated by piezoelectric actuators at resonance frequencies to produce shear stress at the interface between the ice and the support or to produce tensile stress in the ice. Many configurations of de-icing systems using piezoelectric actuators have been tested and showed that piezoelectric actuation may be a viable ice removal system. If the many experimental studies already achieved have the advantage to present tests in different configurations, they often lack analysis of the phenomena, which limits the optimization opportunities. This paper proposes a computational method for estimating voltages and currents of a piezoelectric de-icing system to initiate cohesive fractures in the ice or adhesive fractures at the ice/support interface. The computational method is validated by comparing numerical results with experimental results. Other contributions of this paper are the study of the types of mode (extensional or flexural) and of the frequency range with respect to de-icing performances and the proposal of some general rules for designing such systems while limiting their electric power consumption

Comparison of extensional and flexural modes for the design of piezoelectric ice protection systems

International audienc

Comparison of extensional and flexural modes for the design of piezoelectric ice protection systems

International audienc