Hybrid acoustic and induction-heating systems and methods for impeding formation of ice

An airfoil (200), comprising:

• a skin (210), comprising an external surface (212) and an internal surface (214), opposite the external surface (212), wherein the skin (210) is magnetically and electrically conductive, and wherein the skin (210) has a controlled region (216);
• an interior space (208), formed by the skin (210), wherein the internal surface (214) of the skin (210) faces the interior space (208);
• a leading edge (206) along the external surface (212) of the skin (210);
• and
• a hybrid acoustic induction-heating system (202), configured to impede formation of ice on the external surface (212) of the skin (210) and comprising:
• an induction coil (230) within the interior space (208), wherein at least a portion (236) of the induction coil (230) is sufficiently close to the internal surface (214) of the skin (210) to produce an eddy current (280) within the controlled region (216) of the skin (210) when an alternating electrical current (234) is flowing in the induction coil (230);
• and
• a control system (250), configured to generate inductive heat and acoustic pressure in the controlled region (216) of the skin (210) by supplying the alternating electrical current (234) to the induction coil (230) based, at least in part, on an ambient temperature of a layer of fluid (218) flowing over the external surface (212) of the skin (210).