An ice protection system adapted to protect at least one ice-susceptible flight surface of an aircraft includes a mechanical ice protection device attached to the flight surface. A controller controls a power source that causes the mechanical ice protection device to change in shape and, thereby, change an aerodynamic characteristic of the flight surface. This change in shape happens only when the current thickness of ice on the surface exceeds a minimum thickness.

Active surface structures comprise an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators, and a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a first state, and a second state that is less textured than the first state. Active surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active surface structure is actively controlled.

A method for de-icing or anti-icing an aircraft portion having at least one piezoelectric element fastened on the inner face of the aircraft portion includes, during a design phase of the aircraft portion, placing the piezoelectric element on an area of the aircraft portion to determine frequencies of resonance and increased dynamic coupling, and during the de-icing or anti-icing of the aircraft portion, the same piezoelectric element is excited according to the natural frequencies of the area.

An optimized protection against ice on the inner and outer faces of an aircraft engine nacelle air intake with the air intake including an outer face and an inner face meeting at a line at the longitudinally extreme, called extremum line, an acoustic panel being installed on the inner surface of a part of the inner face. An elimination system based on vibration of the ice formed is put in place on at least a part of the outer face and an ice formation prevention system using a hot fluid is put in place on at least a part of the inner face and either an ice elimination system or an ice formation prevention system using a hot fluid is installed on the inner face and on the outer face, a marking line marking the boundary between the two systems.

An airfoil (100) comprises a skin (110), comprising an external surface (112) and an internal surface (114), opposite the external surface (112). The skin (110) is magnetically and electrically conductive. The airfoil (100) also comprises an interior space (108), formed by the skin (110). The internal surface (114) faces the interior space (108). The airfoil (100) additionally comprises a leading edge (106) along the external surface (112). The airfoil (100) further comprises a hybrid acoustic induction-heating system (102), configured to impede formation of ice on the external surface (112). The hybrid acoustic induction-heating system (102) comprises an induction coil (130) within the interior space (108). At least a portion (136) of the induction coil (130) is sufficiently close to the internal surface (114) to produce an eddy current (180) in the skin (110) when an alternating electrical current (134) is flowing in the induction coil (130). The hybrid acoustic induction-heating system (102) also comprises at least one magnet (140) within the interior space (108). At least the one magnet (140) is configured to produce a steady-state magnetic field (182) within the skin (110).

A method (400) of impeding formation of ice on an exterior surface (104, 204, 304) of airfoil (100, 200, 300) is disclosed. The method (400) comprises detecting (402) first ambient conditions known to cause the ice to form on exterior surface (104, 204, 304). The method (400) also comprises supplying (404) inductive heat and acoustic pressure to exterior surface (104, 204, 304) when the first ambient conditions are detected. The method (400) additionally comprises detecting (406) second ambient conditions known to impede the ice from forming on exterior surface (104, 204, 304). The method (400) further comprises discontinuing (408) to supply the inductive heat and the acoustic pressure to exterior surface (104, 204, 304) when the second ambient conditions are detected.

An airfoil (300) comprises a skin (310), comprising an external surface (312) and an internal surface (314). The skin (310) has a controlled region (316). The airfoil (300) also comprises an interior space (308), formed by the skin (310). The airfoil (300) additionally comprises a hybrid acoustic induction-heating system (302), configured to impede formation of ice on the external surface (312). The hybrid acoustic induction-heating system (302) comprises induction coils (328) and a control system (350). Each one of the induction coils (328) has a portion (336), arranged sufficiently close to the internal surface (314) to produce an eddy current (380) within the controlled region (316). The control system (350) is configured to generate inductive heat and traveling-wave acoustic pressure in the controlled region (316) by supplying different phases (348) of the alternating electrical current (334) to the induction coils (328) based, at least in part, on an ambient temperature of a layer of fluid (318) flowing over the external surface (312).

Methods and systems are generally described that inhibit debris (such as ice) accretions and/or remove debris (such as ice) accretions from the exterior surface of an aircraft. In some embodiments, the invention is a system for an aircraft comprising: a component of the aircraft having a surface; a plurality of piezo-kinetic actuators each positioned proximate to a portion of the surface; and a control unit coupled to the plurality of actuators, the control unit configured to actuate one or more of the actuators at one or more frequencies; wherein the actuators are each configured to introduce a displacement of the surface in three dimensions to inhibit a formation of ice on at least the portion of the surface and to break up existing ice formations on at least the portion of the surface.

Apparatuses for and methods of deicing aircraft surfaces, engine inlets, windmill blades and other structures. Deicing apparatuses can comprise at least one standoff coupled with an actuator and a first region of an inner surface of a skin. A standoff can act as a moment arm and can create efficient, tailorable skin bending and acceleration, breaking an ice to skin bond. Integral as well as modular leading edges can comprise deicing apparatuses.

We describe an ice protection system used for removing ice and/or other accretions from a structure. An actuator, coupled to a structure, is driven to generate vibrations in the structure. A controller drives the actuator using a signal that comprises a frequency chirp over a first period of time, and the controller controls the frequency chirp and the first period such that vibrations generated in the structure by the actuator propagate through the structure to coincide at a desired area of the structure remote from the actuator to remove ice and/or other accretions from the desired area of the structure.