Novel ice protection system suitable for UAV composite wings

Abstract

The existence o f an atmospheric icing th re a t to a irc ra ft operating in moist, low altitudes at temperatures below freezing is well known. The objective o f this study was to develop an a irc ra ft ice protection system suitable fo r a UAV composite wing. Conventional wing leading edge ice protection systems were examined and found to either, necessitate significant electrical power, or were costly with respect to system mass. A low cost and low power technology capable o f protecting the UAV wing leading edge was identified. I t was proposed th a t a commercial magnetostrictive actuator fitte d to and in direct contact with the non-airflow wing surface would provide mechanical impulses to break the ice-wing surface bond. Assuming the accreted ice was o f a form expected o f te s t points in the FAR/ JAR Appendix C flight-icing envelope. Computational simulations demonstrated th a t pairs o f magnetostrictive actuators acting in unison a t a 0.3m span spacing, and deployed along the upper and lower wing leading edge surfaces a t around the 7% chord coordinate, would successfully break the ice-surface bond. I t was estimated th a t fo r a medium endurance UAV o f Predator B class, the proposed system power requirements is 500W at a 45kg total system mass. The proposed system would be more competitive than conventional systems if the use o f consumer grade electronics and control systems, harnessing etc. were permitted, together with the removal o f system redundancy and fail-safe provision requirements necessary fo r manned aircraft. Further work would require the demonstration o f a physical de-icing installation in the icing wind tunnel.