Boeing patents - Quiet, Electric, and Big

Boeing patents - Quiet, Electric, and Big:
rom Things With Wings by Graham Warwick
There is a lot of conceptual design work being done on aircraft configurations that use airframe shielding of engine noise to reduce sound levels at airports, particularly for airliners powered by fuel-miserly open-rotor engines.
Ideally, notes a new US patent granted to Boeing, the reduction in noise would be achieved without adding non-aerodynamic surfaces to the aircraft and without increasing the size or quantity of existing aerodynamic surfaces to provide noise shielding. And that is the idea behind Boeing's configuration below (US patent 8,393,576, filed in Nov 2010).



All graphics: USPTO



The idea is simple, mount the engines on the fuselage so that the open rotors are above the wing, between the rear spar and the trailing edge to shield blade noise on take-off and approach. But, also, ensure that sideline noise from the engines is blocked by designing the wing to bend upwards towards the tip in normal 1-g flight (which the 787's does).


A second new patent relates to Boeing's studies of electrically powered aircraft with extremely low emissions. As the patent notes, a 737-sized airliner traveling 2,000nm would require 22,000lb of jet fuel, but 30,000lb of batteries. Recharging that amount of batteries at the airport during the turnaround between flights is an issue. Fast charging would reduce wait times, but also cut battery life and so increase operating cost.


Boeing's concept (US patent 8,393,580, filed Sep. 2008) uses modular, externally accessible batteries to decouple the turnaround time from the charging rate. Battery pods or packs would be removed and exchanged between flights, to speed turnaround and allow slow ground recharging to increase battery life. The patent illustrates the battery packs in underwing pods (414 and 418, above), or in detachable fairings under the fuselage or engines themselves. And, 787-watchers, the modular battery packs could be jettisoned in flight for safety, the patent notes.
A third new patent looks as though Boeing, after all its trials with the 787's advanced composite airframe, has decided to keep it nice and simple for its next aircraft:


In fact, it is a concept (US patent 8,387,917, filed in Mar 2010) for the space-frame structure of a large cargo aircraft designed to carry ISO-standard freight containers. These 40ft-long intermodal containers are designed so their weight is carried at the four corners, and not spread across the bottom of the container. This would place enormous loads on the flat floor of a conventional cargo aircraft, but in Boeing's design the corners of the containers would plug directly into into the open space-frame structure of the fuselage to carry the load.