Abstract: Propulsors (e.g., an electric motor mechanically coupled to a rotor) are described that passively cool the electric motors via an airflow path through the electric motor and out of the rotors. One embodiment comprises a method of cooling an electric motor. The method comprises operating the electric motor of a propulsor for an aircraft to rotate a rotor of the propulsor, where the rotor has one or more air outlets, and where the electric motor has a housing that includes one or more air inlets in fluid communication with the one or more air inlets. The method further comprises generating, by rotating the rotor using the electric motor, an airflow through the electric motor from the one or more air inlets to the one or more air outlets to cool the electric motor.

Abstract: A power generation system includes an aircraft that includes a propulsor and a platform attached to a structure and configured to support the aircraft. The propulsor is configured to generate electrical power via a wind rotating the propulsor while the aircraft is supported by the platform. A method for using a propulsor of an aircraft to generate electrical power includes positioning the aircraft such that the aircraft is supported by a structure and generating the electrical power via a wind rotating the propulsor while the aircraft is supported by the structure.

Abstract: Propulsors, aircraft including the propulsors, and methods of directing a fluid stream in a propulsor. The propulsors include a housing defining a partially enclosed volume that extends from an inlet to both a first thrust outlet and a second thrust outlet. The propulsors also include a fan assembly including a plurality of blades and a blade pitch control mechanism that is configured to selectively vary a respective pitch angle of each blade in the plurality of blades. The fan assembly is configured to provide a motive force for fluid flow into the partially enclosed volume via the inlet. The propulsors further include an outlet flow control assembly configured to direct the fluid flow to preferentially exit the partially enclosed volume via a selected one of the first thrust outlet and the second thrust outlet. The aircraft include the propulsors. The methods include methods of operating the propulsors.

Abstract: Propulsors (e.g., an electric motor mechanically coupled to a rotor) are described that passively cool the electric motors via an airflow path through the electric motor and out of the rotors. One embodiment comprises a method of cooling an electric motor. The method comprises operating the electric motor of a propulsor for an aircraft to rotate a rotor of the propulsor, where the rotor has one or more air outlets, and where the electric motor has a housing that includes one or more air inlets in fluid communication with the one or more air inlets. The method further comprises generating, by rotating the rotor using the electric motor, an airflow through the electric motor from the one or more air inlets to the one or more air outlets to cool the electric motor.

Abstract: Propulsors, aircraft including the propulsors, and methods of directing a fluid stream in a propulsor. The propulsors include a housing defining a partially enclosed volume that extends from an inlet to both a first thrust outlet and a second thrust outlet. The propulsors also include a fan assembly including a plurality of blades and a blade pitch control mechanism that is configured to selectively vary a respective pitch angle of each blade in the plurality of blades. The fan assembly is configured to provide a motive force for fluid flow into the partially enclosed volume via the inlet. The propulsors further include an outlet flow control assembly configured to direct the fluid flow to preferentially exit the partially enclosed volume via a selected one of the first thrust outlet and the second thrust outlet. The aircraft include the propulsors. The methods include methods of operating the propulsors.