The Boeing Company

Michael S Hoag

Mark Stephen Shander

John T Paterson

Michael L Drake

Casey Y K Ng

Richard A Cote

Howard Carter, Iii

John T Peters

Steven K Plank

An electrical architecture for an aircraft is provided. The electrical architecture is particularly suitable for relatively small, compact, and lightweight aircraft. In one embodiment, the electrical architecture includes an electrical generator component coupled to the aircraft engine, and an air compression system coupled to the electrical generator component. The electrical generator component is configured to receive mechanical power from the engine and to generate a constant frequency AC electrical power from the engine mechanical power, and the air compression system is configured to receive the constant frequency AC power as an input and, in response thereto, produce a pressurized air output having variable characteristics (for example, a variable flow rate or a variable air pressure).

Electrical systems architecture for an aircraft, and related operating methods

A passive cooling system for an auxiliary power unit (10) located in an aft compartment (20) of an aircraft is provided in which cooling air is drawn into the compartment through an aft opening (54) located in the rear of the aircraft and discharged back to the atmosphere through an exhaust duct (42) connecting to a rear exhaust opening (44). The aft opening (54) is located above the exhaust opening (44). Cooling air is drawn into the compartment using an eductor (46) that is connected between a turbine (14) and the exhaust duct (42). The eductor (46) creates a low-pressure region that suctions compartment air, which in turn, suctions atmospheric air in through the aft opening (54). The combined compartment air and combustion gases are exhausted out the exhaust duct (42). In auxiliary power unit embodiments in which the compartment is located in a rear portion of the aircraft fuselage, the cooling system further includes an inlet duct (50) having a forward end (56) and an aft end (52). The aft end (52) is connected to the opening (54); the forward end (56) is connected to the compartment (20). The inlet duct (50) defines an airflow passage through which ambient air is drawn into the compartment (20) for use in cooling various auxiliary power unit components.

Auxiliary power unit passive cooling system

Growing community of inventors

Kent, WA, United States of America

Michael S Hoag