SYNOPSIS: THEY COME IN ALL SIZES...THESE MOVERS OF EVERYTHING FROM LET ???UCE TO STEEL. THEIR?
Aerodynamic Truck Tests
Variety of Trucks on San Diego Freeway
Cut to recreational vehicles and other trucks
Saltzman on-camera sync
Intercut more van runs
FRO front sign and small van on runway
Intercut shots of HL/10 and X-15
Intercut stopwatches, and other interiors, Speedometer
Install air shield
Ejecting diatomaceous earth
"The thing that we are all interested in, of course, is the savings in fuel, the miles per gallon that we can achieve, rather than the aerodynamic drag per se. The aerodynamic improvements that we have experienced so far are translatable into fuel savings, say, at cruise conditions when you are going down the highway at highway speeds somewhere in the neighborhood of, oh, 15 percent, perhaps 20 percent savings in fuel."
"The experience and background that we have here at the NASA Flight Research Center that bears on tests such as this goes back to the aerodynamics experiments that we have done on various aircraft, and really the means of achieving aerodynamic efficiency on aircraft isn't that different than it is on automobiles and trucks excepting, of course, on trucks and automobiles you are working at lower speeds."
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Background: SYNOPSIS: THEY COME IN ALL SIZES...THESE MOVERS OF EVERYTHING FROM LET ???UCE TO STEEL. THEIR BOX-LIKE SHAPES ALLOW THE PACKING OF HIGH-VOLUME LOADS.
IT'S BELIEVED THAT BOTH TRUCKS AND RECREATIONAL VEHICLES LIKE THIS CAN BE MADE MORE ECONOMICAL TO OPERATE. IN THE PAST, AS TRUCKS WERE MANUFACTURED LARGER AND LARGER. ENGINE SIZE WAS INCREASED TO HANDLE THE HEAVIER LOADS. NOW, WITH THE CONTINUING FUEL PROBLEMS, ENGINEERS ARE ATTEMPTING TO MAKE THE BIG TRUCKS MORE EFFICIENT.
IN A JOINT EFFORT, NASA AND THE DEPARTMENT OF TRANSPORTATION ARE IN THE MIDST OF A RESEARCH PROGRAM TO DO JUST THAT.
THE METHOD USED TO DEFINE DRAG IS KNOWN AS THE "COAST-DOWN" METHOD. AFTER ACCELERATING THE TRUCK TO SIXTY-FIVE-MILES-PER-HOUR, THE GEARS ARE DISENGAGED AND THE TRUCK IS ALLOWED TO COAST. THE DECELARATION IS MONITORED CLOSELY BECAUSE THE TIME IT TAKES TO SLOW DOWN CAN BE DIRECTLY CONVERTED INTO DRAG. SO FAR, AERODYNAMIC DRAG HAS BEEN DECREASED A LITTLE OVER 50 PERCENT.
OTHER SECONDARY BENEFITS INCLUDE LESS POLLUTION AND INCREASED ENGINE LIFE.
THE TESTS ARE BEING DONE AT NASA'S FLIGHT RESEARCH CENTER NEAR THE MOJAVE DESERT IN CALIFORNIA ON AN AUXILLARY RUNWAY. PROJECT ENGINEER ED SALTZMAN EXPLAINS.
STARTING WITH A SMALL DELIVERY VAN, ED SALTZMAN AND HIS TEAM OF ENGINEERS RE-SHAPED THE VEHICLE WITH SHEET METAL. THE TEST TRUCK HAS EVOLVED FROM A SQUARE BOX TO ITS PRESENT SHAPE WITH ROUNDED CORNERS. THE MAJOR EMPHASIS HAS BEEN ON THE ELIMINATION OF DRAG...WIND RESISTANCE THAT FORCES THE ENGINE TO WORK HARDER.
THIS BIG TRACTOR TRAILOR, TYPICAL OF MANY ON U.S. HIGHWAYS, IS ALSO BEING STUDIED.
HERE, ENGINEERS ATTACH ONE OF MANY ADD-ON DEVICES THAT WILL MODIFY AIR-FLOW AROUND THE TRUCK, AND HOPEFULLY REDUCE DRAG.
TO HELP THEM VISUALIZE THE FLOW OF AIR PATTERNS, SIX-INCH-LONG STRINGS, OR TUFTS, ARE ATTACHED AND PHOTOGRAPHED. THESE HAVE BEEN USED IN AERONAUTICAL RESEARCH FOR YEARS.
ANOTHER METHOD INVOLVES PUMPING A POWDER-LIKE SUBSTANCE OVER THE TRUCK AS IT TRAVELS ALONG. THE LARGE TRACTOR-TRAILER PROGRAM HAS JUST BEGUN, AND IT'S TOO SOON TO PREDICT HOW MUCH FUEL MIGHT BE SAVED AS A RESULT OF THE TRUCK MODIFICATIONS. A FUEL SAVINGS OF AS LITTLE AS FIVE PERCENT HOWEVER.