Greg Twatchman / Washington DC
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| Models of the 747-8 have completed over 3,000h of windtunnel testing |
Boeing has tweaked the design of the 747-8 family following the latest round of windtunnel tests. Changes include the adoption of partial fly-by-wire control systems and wing improvements, including drooped ailerons.
The manufacturer conducted three months of high- and low-speed windtunnel testing on models of the aircraft – a milestone in a programme that intends to freeze the 747-8’s final configuration in October.
High-speed tests were conducted at Boeing’s Seattle facilities using a 3%-scale 747-8F model 2.2m (87in) long with a wingspan of 1.9m. Low-speed and noise tests were performed on a 5%-scale 747-8 model at the Farnborough, UK facilities of engineering and consultancy firm Qinetiq.
More than 3,000h of windtunnel testing have been completed. The next tests will be conducted in a high-pressure tunnel to provide a closer simulation of actual flight conditions providing data allowing structural engineers to design parts to tighter tolerances.
“The focus of these latest tests was to finalise the aerodynamic lines of the aircraft and begin the development of design loads,” says Boeing chief engineer of 747-8 product development, Roy Eggink.
The latest wing rendition, which was chosen at the end of April after undergoing further tweaks to eke out better cruise performance, also increases fuel capacity while maintaining the planned efficiency improvements of the larger design.
Fuel consumption is expected to be around 2.6 litres/passenger per 100km for the -8 versus 3.06 litres for the 747-400 assuming a 100% load factor and a 5,550km (3,000nm) mission range.
Fuel capacity for both passenger and freight models has grown by 14,000 litres (3,700 US gal) to 241,590 litres for the Intercontinental and 229,100 litres for the -8F.
Source: Flight International
