March_2022_AMP_Digital

1 3 A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A R C H 2 0 2 2 Fig. 1 — Testbed 80, located at Rolls-Royce in Derby, U.K. T he transition to a lowcarbon glob- al economy is a challenge that has been continually addressed by the aerospace industry. Emissions per passenger kilometer have been re- duced by 80% since the first gener- ation of commercial jet aircraft, and today aviation is currently responsible for about 2% of annual carbon dioxide emissions [1] but recognizes the need to continue to decarbonize. Recently, the International Air Transport Association (IATA) approved a resolution for the global air transport industry to achieve net-zero carbon emissions by 2050 [2] . Propulsion for aerospace will play a fundamental role in enabling this transition, including emerging and dis- ruptive products incorporating hybrid or fully electric and hydrogen tech- nologies for the personal mobility and regional aircraft market. For larger air- craft engines however, fuel efficien- cy gains will come from improved gas turbine engine architectures and ad- vanced materials for the foreseeable fu- ture. Additionally, the development of sustainable, non-fossil-sourced alterna- tive fuels will have a critical role in de- coupling carbon growth from market growth. Demonstration of these novel technologies in current and future large gas turbine engines for civil aerospace constitutes a crucial step to verify per- formance and ensure safe operation. Before flight, ground-based testing provides essential information under a range of controlled conditions to better understand performance, operability, and reliability. In 2021, aircraft engine manufacturer Rolls-Royce officially un- veiled Testbed 80 (Fig. 1), the world’s largest and most advanced indoor aero- space test facility, to demonstrate the technologies that will improve propul- sion efficiency and support the over- arching objectives for sustainable aviation and the transition to a net-zero carbon future. TESTBED 80 FACTS AND FIGURES Testbed 80, located in Derby, U.K., was built at a cost of £90M ($120M US) and took 4.5 years to design and of the test bed, a blast basket measur- ing 17 m long and 6.5 m in diameter dissipates the energy of the exhaust system. Testbed 80 can accommodate sev- eral key tests crucial for ensuring safe operation of gas turbine engines, in- cluding fan blade-off, bird ingestion, sand ingestion, and core water inges- tion. Other types of measurements required for regulatory approvals such as noise, emissions, and cabin air quality are also possible. X-ray technology is used in the test cell to inspect geometrical clearances construct. The massive scale of the project (Fig. 2) can be appreciated by the following metrics: • The internal area measures 7500 m 2 and the construction site required the removal of excavated earth to fill nearly 2000 trucks • 27,000 m 3 of concrete were poured for seven months and was poured for 60 days straight at the height of construc- tion • The surrounding walls of the test cell measure 1.5 to 1.7 m in thickness • Over 3000 tons of steel were used in the con- struction • The lift platform for engines can raise loads up to 10 tons to a height of 5.5 m Aerodynamic design of the test cell incorporated lessons learned over the years from other facilities and was supported by aerodynamic and acous- ticmodelling done in collaboration with the National Research Centre in Ottawa. Augmented air within the test cell flows at a rate of 4.2 tons/s to simulate max- imum take-off conditions with replen- ishment every 3 s. Turning vanes split the flow of air into the test bed and en- sure it is evenly distributed. At the rear