A rotor blade assembly for a wind turbine includes at least one rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root. The surfaces are constructed of a polymeric composite material. The rotor blade assembly also includes a protection cap arranged adjacent to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade. The protection cap includes a body defining an overall length. Further, at least a first segment of the protection cap is constructed of a tungsten-based metal. Thus, the protection cap is configured to reduce erosion and resist corrosion of the rotor blade caused by particle or liquid impact.

An airfoil that includes an airfoil body having a root and a tip, and convex and concave sides that extend between a leading edge and a trailing edge. The airfoil also includes at least a first cladding element that is attached to the airfoil body. The first cladding element includes a first portion and a second portion. The second portion is configured to separate from the first portion when the first cladding element encounters a force of at least a predetermined amount.

A proprotor blade for a ducted aircraft including a duct includes a main body having a distal end and a sacrificial blade tip coupled to the distal end of the main body. The sacrificial blade tip includes a deformable core material and a shell layer at least partially covering the deformable core material. The sacrificial blade tip deforms upon contact with the duct, thereby reducing damage to the ducted aircraft.

A proprotor system for a ducted aircraft includes a duct and proprotor blades surrounded by the duct. Each proprotor blade is rotatable about a respective pitch change axis. The proprotor blades are configured to change collective pitch about the pitch change axes. The proprotor blades are extendable along the pitch change axes into various positions including a retracted position and an extended position. The proprotor blades change between the retracted position and the extended position based on the collective pitch of the proprotor blades, thereby controlling a tip gap between the proprotor blades and the duct.

A blade de-icing system for a blade to be de-iced that has a body extending between a leading edge and a trailing edge, said leading edge ending at an apex. The system includes a de-icer component having a recess formed therein and being positioned on said leading edge of said blade so that said de-icer component covers and extends away from said apex and so that said recess is positioned at said apex of said leading edge; and an anti-erosion strip provided in said recess of said de-icer component; wherein said anti-erosion strip and said recess are sized and shaped such that said anti-erosion strip fits within said recess so that outer surface of said anti-erosion strip is flush with the outer surface of said de-icer component. A method of manufacturing the same is also described herein.

A fan blade anti-icing system comprises a fan hub and a fan blade extending radially outwardly from the fan hub. The fan blade has a base and an airfoil extending radially outwardly from the fan base. The airfoil having a leading edge, a trailing edge, a convex side surface between the leading and trailing edge and a concave side surface between the leading and trailing edge. The fan blade further has a radial passage extending from a blade air inlet in the blade base in communication with a source of heated air, and a rearwardly directed passage in communication with the radial passage and having a blade air outlet forward of the trailing edge and oriented tangentially to the convex side surface or concave side surface of the airfoil.

A fan blade anti-icing system comprises a fan hub and a fan blade extending radially outwardly from the fan hub. The fan blade has a base and an airfoil extending radially outwardly from the fan base. The airfoil having a leading edge, a trailing edge, a convex side surface between the leading and trailing edge and a concave side surface between the leading and trailing edge. The fan blade further has a radial passage extending from a blade air inlet in the blade base in communication with a source of heated air, and a rearwardly directed passage in communication with the radial passage and having a blade air outlet forward of the trailing edge and oriented tangentially to the convex side surface or concave side surface of the airfoil.

A rotor blade assembly for a wind turbine includes at least one rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root. The surfaces are constructed of a polymeric composite material. The rotor blade assembly also includes a protection cap arranged adjacent to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade. The protection cap includes a body defining an overall length. Further, at least a first segment of the protection cap is constructed of a tungsten-based metal. Thus, the protection cap is configured to reduce erosion and resist corrosion of the rotor blade caused by particle or liquid impact.

A protective coating composition for providing protection to a component of a ram air turbine system in need thereof. The protective coating composition comprises an aqueous-soluble or alkaline-soluble polymer matrix, one or more compressible fillers, and one or more non-compressible fillers. The disclosure also provides a method for providing a protective coating onto components of a ram air turbine system in need thereof for providing indentation and scratch resistance thereto.

Anti-icing stacks for protecting an aerodynamic surface are described. In some embodiments, an anti-icing stack includes an anti-icing layer, an elastomeric erosion protection layer, and an additional layer. The erosion protection layer is disposed between the anti-icing layer and the additional layer. The additional layer has a thickness greater than the thickness of the erosion protection layer and a tensile modulus of no more than the tensile modulus of the erosion protection layer. The additional layer may be a foam adhesive layer.