New technology could make trucks more 'green'

February 16, 2010 8:05:21 PM PST
If you have ever stood by a highway and felt the blast wave of a large truck passing by, that experience may become a thing of the past, or at least, one greatly reduced. If and when that happens, thank a researcher at Lawrence Livermore Laboratory and an experiment he brought to the world's largest wind tunnel at Nasa Ames in Mountain View.

"What happens is this trailer is going to have a wake, " explained Dr. Kambiz Salari, who has spent ten years studying how large trucks move the air, and how that same air creates aerodynamic drag on them. His research could save the nation's truckers 3.4 billion gallons of diesel a year and has the industry's attention.

"Well, if I said I could save you a 1/100th of a mile per gallon, that's a million dollars. Would you put a $1 million in your pocket?" asked Steve Bruford, a vice-president of product development at Navistar Trucks.

Essentially, this research provides common ground for two competing efficiencies. For trucks, a box is the most effective shape for carrying cargo, but aerodynamically it is inefficient. So, Dr. Salari has been working on ways to retain the box shape while streamlining it. His solution is bolt-on drag-defeating technology.

At a cursory glance, an 18-wheeler recently tested in NASA's wind tunnel looked much like ones seen on the road. But, a closer examination revealed devices on the hood, between the cab and trailer, beneath the trailer itself, and also behind it. They alter differences in air flow and pressure, especially at high speed.

The testing measured their combined benefit in reducing drag. Dr. Salari designed them to be adaptable for models now on the road. His hope is that such modifications will pay for themselves in a year of driving or less.

"It's a big deal if you have thousands of trucks and you spend $1.2 billion in fuel in a year," said Bruford. "If I can make a fifty percent reduction, it's a big deal."

More important, it represents a textbook case of green technology saving fuel and lowering carbon dioxide consumption for the most pragmatic of reasons, profit.