Wind turbines and wind turbine rotor blades with reduced radar cross sections
Wind turbine rotor blades include a shell having a leading edge opposite a trailing edge, a structural support member that supports the shell and is disposed internal the wind turbine rotor blade between the leading edge and the trailing edge and extends for at least a portion of a rotor blade span length, and a resistive cellular support structure disposed at least partially about the wind turbine rotor blade that physically supports at least a portion of the wind turbine rotor blade and at least partially absorbs radar energy.
1. A wind turbine rotor blade comprising:
a shell comprising a leading edge opposite a trailing edge;
a structural support member that supports the shell and is disposed internal the wind turbine rotor blade between the leading edge and the trailing edge and extends for at least a portion of a rotor blade span length; and,
a resistive cellular support structure disposed at least partially about the wind turbine rotor blade that physically supports at least a portion of the wind turbine rotor blade and at least partially absorbs radar energy, wherein the resistive cellular support structure comprises a plurality of open structural cells comprising a plurality of cell walls that form a plurality of cell passages, and wherein the structural support member at least partially comprises the resistive cellular support structure.
2. The wind turbine rotor blade of claim 1 , wherein the plurality of open structural cells comprise a honeycomb configuration.
3. The wind turbine rotor blade of claim 1 , wherein the resistive cellular support structure comprises a variable amount of resistive material.
4. The wind turbine rotor blade of claim 1 , wherein the structural support member comprises fiberglass.
5. The wind turbine rotor blade of claim 4 , wherein the structural support member comprises a spar disposed between an upper spar cap and a lower spar cap.
6. The wind turbine rotor blade of claim 1 , wherein the shell at least partially comprises the resistive cellular support structure.
7. The wind turbine rotor blade of claim 6 , wherein the structural support member comprises carbon fiber.
8. A wind turbine rotor blade comprising:
a shell comprising a leading edge opposite a trailing edge;
a structural support member that supports the shell and is disposed internal the wind turbine rotor blade between the leading edge and the trailing edge and extends for at least a portion of a rotor blade span length;
a first resistive cellular support structure disposed at least partially about a first location of the wind turbine rotor blade that physically supports at least a portion of the wind turbine rotor blade and at least partially absorbs radar energy, wherein the first location comprises the structural support member; and,
a second resistive cellular support structure disposed at least partially about a second location of the wind turbine rotor blade that physically supports at least a portion of the wind turbine rotor blade and at least partially absorbs radar energy.
9. The wind turbine rotor blade of claim 8 , wherein the second location comprises the shell.
10. The wind turbine rotor blade of claim 9 , wherein the structural support member comprises fiberglass.
11. The wind turbine rotor blade of claim 9 , wherein the structural support member comprises carbon fiber.
12. The wind turbine rotor blade of claim 8 , wherein the first resistive cellular support structure has a first amount of resistive material and the second resistive cellular support structure has a second amount of resistive material greater than the first amount.
13. The wind turbine rotor blade of claim 8 , wherein the first resistive cellular support structure has a first orientation and the second resistive cellular support structure has a second orientation different than the first orientation.
14. A wind turbine comprising:
a nacelle comprising a rotor hub mounted on a tower;
a plurality of wind turbine rotor blades connected to the rotor hub, wherein at least one of the plurality of wind turbine rotor blades comprises:
a shell comprising a leading edge opposite a trailing edge;
a structural support member that supports the shell and is disposed internal the wind turbine rotor blade between the leading edge and the trailing edge and extends for at least a portion of a rotor blade span length; and,
a resistive cellular support structure disposed at least partially about the wind turbine rotor blade that physically supports at least a portion of the wind turbine rotor blade and at least partially absorbs radar energy, wherein the resistive cellular support structure comprises a plurality of open structural cells comprising a plurality of cell walls that form a plurality of cell passages, and wherein the structural support member at least partially comprises the resistive cellular support structure.
15. The wind turbine of claim 14 , wherein each of the plurality of wind turbine rotor blades comprises the resistive cellular support structure.
16. The wind turbine of claim 14 , wherein the plurality of open structural cells comprise a honeycomb configuration.
17. The wind turbine of claim 14 , wherein the resistive cellular support structure comprises a variable amount of resistive material.