Aurora D8

Source: Wikipedia, the free encyclopedia.
D8
NASA / Aurora D8 airliner concept
Role Wide-body jet airliner concept
National origin United States
Manufacturer Aurora Flight Sciences
Designer Mark Drela[1]
Status Development and testing

The Aurora D8, also known as the D8 Airliner, is an airliner concept under development as of mid 2017.[2] The project was initiated in 2008 by Aurora Flight Sciences, the Massachusetts Institute of Technology (MIT) and Pratt & Whitney under NASA's sponsorship of $2.9 million (£2.19 million).[3]

Aurora is refining the fuel-efficient D8 designed for NASA by MIT, and originally hoped to fly a half-scale demonstrator in 2022.

Airbus A320 and could be in test service by 2027 at the earliest and 2035 at the latest.[5]

Aurora Flight Sciences was purchased by Boeing on November 8, 2017 for their drone developments. The subsidiary is intended to accelerate Boeing's development of autonomous technology.[6]

Design

The side-by-side "double bubble" fuselage provides additional lift along the nose section as well as faster turnaround owing to its wider fuselage. As a result, smaller wings can be used to generate lift which reduces drag. The mounting of the engines at the rear end of the D8 instead of below the wings used in conventional aircraft design allows reduction of thrust requirements by minimizing inefficiency from Boundary Layer Ingestion (BLI). This results in the ability to use smaller and lighter high bypass ratio engines.[2]

However, the chassis features less radical than competing

Boeing 737-800.[7]

Engines

Clustering the engines together atop the wide tail of a flattened fuselage enables them to reenergize the slow-moving boundary layer over the fuselage to increase efficiency, and allow a clean, low drag, high aspect ratio wing. Starting with slower flow, the reduction in

exhaust velocity increases the propulsive efficiency with a similar specific thrust
. By ingesting and reenergizing the boundary layer flow, BLI reduces by 40% in the D8 the wasted kinetic energy in the combined high-velocity jet exhaust and slow-speed wake behind the fuselage. Large-scale
mass flow
. The BLI benefit is an order of magnitude more than the loss from ingesting distorted boundary-layer flow.[8]

A large fan size is needed to exceed a 20:1 bypass ratio. Developed by United Technologies Research Center, a distortion-tolerant fan was scale tested at NASA and coped with flow distortion from ingesting the boundary layer close to the upper fuselage surface. As a compact core limits blade

PT6
arrangement, with hot gas discharged forward through a low-pressure power turbine connected to the fan via a short shaft and a gearbox. To avoid the risk of an
uncontained engine failure
causing the second engine to fail, the cores are angled by 50° since they are no longer mechanically linked to the fan, with low pressure losses since only the core flow is turned. Not connected to the power section, the core can be disassembled for maintenance.[8]

See also

References

  1. ^ "New Airplane Design Could Reduce Greenhouse Gas Emissions". Scientific American.
  2. ^ a b "D8 ULTRA-EFFICIENT COMMERCIAL AIRCRAFT" (PDF). aurora.aero. Archived from the original (PDF) on November 20, 2021. Retrieved April 8, 2017.
  3. ^ "Program Overview". aurora.aero. Retrieved April 8, 2017.
  4. ^ Yutko, Brian; Wirsing, Larry; Church, Clint; Chambers, Jeffrey (2 May 2018). "Demonstrating FAA Certifiable Ultra-Efficient Commercial Aircraft Configurations" (PDF). FAA CLEEN-II Public Session. Federal Aviation Administration. Retrieved 30 January 2022.
  5. ^ Gipson, Lillian (2 March 2015). "The Double Bubble D8". nasa.gov. NASA. Retrieved April 8, 2017.
  6. ^ "Boeing Completes Acquisition of Aurora Flight Sciences". Boeing (Press release). November 8, 2017. Retrieved August 1, 2019.
  7. ^ Graham Warwick (January 18, 2017). "Aurora Refines Design Of Ultraefficient D8 Airliner". Aviation Week & Space Technology.
  8. ^ a b Guy Norris and Graham Warwick (March 26, 2015). "A Reversed, Tilted Future For Pratt's Geared Turbofan?". Aviation Week & Space Technology.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Aurora_D8&oldid=1215930200"