Pneumatic Technology Could Dramatically Boost Heavy-Truck Fuel Economy

Diesel Fuel News, May 28, 2001 by Jack Peckham

Little air jets installed in key locations on tractor-trailer rigs could dramatically cut drag and thus boost diesel fuel efficiency, Georgia Tech Research Institute (GTRI) discovered in recent modeling tests.

Just-reported test results follow an extensive research program supported by U.S. Department of Energy (DOE) office of heavy vehicle technologies (OHVT).

Model-scale testing of the so-called "Pneumatic Heavy Vehicle" technology indicates it's possible to get 50% drag reductions (using only 1 pound/square inch blowing pressure) and over 80% drag reduction "if additional blowing air were available," GTRI researcher Robert Englar explained in a paper to Society of Automotive Engineers government/industry meeting this month (see: SAE 2001-01-2072).

* 10 MPG Trucks Seen Possible

Conceivably, the technology eventually could lead to the still-dreamed-of 10 miles/gallon economy goal of the joint industry/DOE "21st Century Truck Program," OHVT director James Eberhardt recently revealed (see Diesel Fuel News 5/14/2001, P5).

Because of the outstanding results of the 18-month GTRI/DOE test modeling program, Volvo Trucks (North America) and Great Dane Trailers (Georgia) have agreed to supply two new tractor-trailer rigs, for full-scale SAE Type II fuel economy tests this summer.

"We will build a duplicate of our best wind-tunnel pneumatic configuration, to be added to the back of one trailer," GTRI's Englar told us. "Blowing air will be supplied at this point by an on-board compressor or blower, and emphasis will be totally on fuel economy."

The test program (results expected to be available this fall) is in cooperation with American Trucking Associations -- whose members potentially could enjoy a huge fuel economy benefit from the technology.

* Big Safety Gains, Too

Meantime, U.S. Dept. of Transportation's National Highway Traffic Safety Administration (NHTSA) has expressed interest in the many other safety aspects of pneumatic technology, including increased braking, increased traction on wet/icy roads, better lateral/directional rig stability, rapid response and anti-jack-knifing potential, Englar explains. So, a second series of safety-oriented tests might follow the fuel-economy tests, he said.

The pneumatic devices, plus a closely-related low-drag aerodynamic heat exchanger radiator, "are already patented by GTRI and should they perform as well as we expect, licensing will be available through us for new-vehicle installation or for aftermarket applications," Englar explains.

"Since our research and development emphasis has been on small, simple and effective aero devices, we would expect the system cost to be quite reasonable.

"Add-ons to the back of the trailer are expected to be 9-inch length or less. Actual system cost will be determined after testing and design of production-model device installation."