More than 1,000 passengers could exit a blended wing body airliner within the 90s legal requirement, say London based-University of Greenwich researchers.

Simulations using Greenwich's aircraft evacuation model, AirExodus, were confirmed by a live exercise involving a large scale-BWB partial cabin mock-up and more than 700 volunteers over two days. Held in February, the mock-up comprised the rear, port-side cabin area. Managed by UK company Cranfield Aerospace, each day had four trials using over 350 members of the public aged from 18 to 50.

The simulation and trials assumed only that only the exits on one side, and across one half of the aircraft's rear, could be used for the evacuation. The project's BWB configuration has 20 possible exits and its engines are slung under the wings, rather than on top and at the rear.

797 BWB mock-up
 © Boeing

As AirExodus had previously been used for conventional aircraft studies, the software had to be developed to predict how passengers behave in the BWB's more expansive layouts and how people interact with the high number of internal aisles to find an exit.

"With eight aisles the [BWB] is almost as wide as it is long, making it more like a flying auditorium than a traditional tubular aircraft," says University of Greenwich fire safety engineering group director and UK Civil Aviation Authority professor of mathematical modelling, Edwin Galea. He says the exit door locations were selected by Airbus on the basis of their compatibility with the BWB's structural integrity. A challenge for BWB designs is pressurising their large internal non-cylindrical volumes, which has implications for door locations.

Galea's group linked AirExodus with Smartfire, a computational fluid dynamics model of fire, so the virtual passengers experience the heat and smoke. The researchers use this combination to generate numbers of injuries and fatalities.

This work is part of the Airbus led-European Union Sixth Framework project New Aircraft Concepts Research project. This euros 30 million ($47 million), four-year project has 36 partners from 14 nations. Galea presented the group's findings at the second NACRE conference held at the University of Greenwich from 8-10 July.

Source: Flight International