美国航空航天局科学家测试新型飞机

The U.S Aeronautics and Space Administration, NASA, is commonly associated with space exploration, but aeronautics is still a big part of the agency’s research. Engineers at its Aeronautics Research Center, in Hampton, Virginia, are testing new ideas that someday may produce lighter, quieter and less polluting aircraft.

By 2030, NASA would like to see planes that burn 60 to 70 percent less fuel, pollute less and are quieter than 2005 models.

Scientists say achieving those goals calls for lightweight materials, better aerodynamics, new kinds of fuels and alternative aircraft configurations.

In NASA's huge Transonic Dynamics Wind Tunnel, engineers are testing a new design of airplane wing made of a composite material that is considerably lighter than the industry standard, aluminum alloy.

Senior aerospace engineer Robert C. Scott says in the future, wings will likely be made out of materials like this.

“With advances in material, advances in design and analysis capability and the need for higher efficiency, you’re driving yourself toward very lightweight designs," said Scott.

One of those designs is the long, truss-supported wing, says project scientist Richard Wahls.

“That allows you to stiffen the wing, keep the wing thin, grow the span to reduce drag," said Wahls.

If someone decides to build one of these advanced configurations, they will be able to use the results of tests done by NASA.

In another part of the center, researchers are testing a new way of manufacturing composite materials.

Instead of aligning the fibers in straight, parallel lines, these fibers are molded around the points of heavy load, explains materials research engineer Karen Taminger.

“That allows the fibers to continue to carry the load all the way around the corners instead of being interrupted if we cut that out from a straight aligned composite," said Taminger.

Taminger says new structural designs will allow manufacturers to reduce the weight of airplanes and make them more energy efficient.

NASA researchers also want to reduce the pollution that comes out of airplane engines, says Fay Collier, who manages the Environmentally Responsible Aviation project.

“We want to take advantage of alternative fuels and the emergence of alternative fuels, and we want to design advanced combustors to minimize the output," said Collier.

To learn what's in the exhaust of an airplane burning a mixture of petroleum and alternative-based fuel, NASA scientists fly a second plane right behind the first one. On-board sensors measure the percentage of pollutants contained in different fuel mixtures.

Project scientist Richard Wahls says NASA is constantly looking for ways to revolutionize aviation.

“We hope to find technologies that we can accelerate forward through the research, but other technologies - they may not be possible for 20 or 30 years," he said.

In the meantime, he says, there are incremental improvements moving the aviation industry towards better, safer and more efficient aircraft.