Friday, June 3, 2011

Boeing`s new "green" planes

Boeing’s two newest planes, the 787 Dreamliner and the 747-8, are designed to be more fuel efficient and thus reduce carbon emissions, according to Boeing’s latest sustainability report. The Dreamliner is designed to be 20 percent more fuel efficient than previously comparable aircraft. The 747-8 will provide 16 percent better fuel economy than previous 747 renditions and emit 16 percent less CO2. Additionally, Boeing will offer improvements to existing planes. In 2012, Boeing will begin flying an “ecoDemonstrator 737” to test low emissions technologies.

Boeing has the following environmental targets for its U.S. operations:
  • 25 percent reduction in greenhouse gas emissions
  • 25 percent reduction in energy consumption
  • 25 percent reduction in water intake
  • 25 percent reduction in hazardous waste generation
  • 75 percent decrease in solid waste sent to landfills
The report details the progress Boeing has made to meet its environmental targets. Since 2002, the company reduced carbon emissions 28 percent, energy use 30 percent, hazardous waste 44 percent and water use 41 percent. In 2010, Boeing reduced absolute energy consumption by three percent, and absolute water intake by five percent compared to 2009. Last year, Boeing also diverted 73 percent of its solid waste generated from landfills, up from 68 percent in 2009.

How does Boeing plan to achieve this?

Courtesy: US Patent Office

1) Using composite materials for the aircraft structures, like the fuselage, which lead to lesser weight and hence greater fuel efficiency. Typically the case with the Boeing 787.
2) Experts are speculating that Boeing is using a sophisticated aerodynamic technique known as hybrid laminar flow control (HLFC) .

 Boeing has revealed very little so far about the laminar flow system ( see the image above), which would be the first application of its type on any commercial airliner. The laminar flow system reduces drag by sucking the turbulent boundary layer in through tiny holes in the skin to a plenum, or hollow chamber, inside the leading edge of the fin or stabilizer. Unlike experimental large-scale systems demonstrated in the past by NASA amongst others, the HLFC device under study for the 787 is essentially passive. This is important because passive systems are less complex, and lighter. 

Active systems, by contrast, require a turbocompressor, or other mechanical device, to suck the air into the wing. Assuming the patent forms the basis for the 787 system, the flow through the system is generated by passageways which vent the air to local areas of low pressure. These areas are located in areas such as the tips of the fin and stabilizers, and created by the motion of the aircraft itself. The drawings appear to indicate control of the flow via vent doors, similar to those seen on current environmental control system outlet ducts. 

However, much about this technology is being developed by Boeing and they have been very secretive about their work.A clear picture will arise only when the "Green" planes take to the skies.