Issue link: https://read.dmtmag.com/i/630222
A erodynamic characteristics around the fifth wheel and the trailer's rear are difficult to manage. The trailer gap is a necessary open space that allows for full articulation as the rig maneuvers in tight sur- roundings. But in aerodynamic terms, that massive gap is a huge drag inducer on the entire vehicle. At highway speeds, as air flows past the tractor heading for the trailer, it encounters a large vacuum area created by the gap's open space. The same holds true for the back of a trailer. As air passes around it, a natural vacuum forms behind the vehicle that air seeks to fill. The result is drag, which leads to aero- dynamic inefficiency. Drag makes a vehi- cle more difficult to move down the road efficiently. The engine must work harder to overcome it, burning more fuel as a consequence. Smart fleet managers understand the importance of reducing these large areas of turbulence and drag. Fortunately, trac- tor-trailer aerodynamics have become bet- ter understood in recent years, leading to new devices that help smooth airflow past the trailer gap and behind the trailer. "Until about 2000, tractors and trailers were really manufactured in isolation from each other," says Kent Smerdon, vice presi- dent of international marketing for Aero- serve Technologies, which manufactures and sells Airtab vortex generators. "This concept is changing, with the industry appreciation that a large gap is an aerody- namic and fuel problem area." Today's aerodynamic innovations in- clude high-rise condo – or load-height matching – full fairings and side extend- ers. "From the trailer side of the equation, rounded front corners and devices such as nose cones have helped with drag reduc- tion efforts," Smerdon says. Jeff Grossmann, director of engineering for aerody- namic device manufacturer Stemco, believes that North American truck fleets have learned that closing the trac- tor-trailer is the easiest way to save fuel and improve fuel economy. "Just closing the gap a mere five inches – from 50 to 45 inches, for example – offers fleets large and imme- diate fuel savings," Grossmann says. Tackling the total package Smerdon says that although OEMs have improved their designs for more aerody- namic efficiency, fleet managers should understand that only the separate tractor and trailer have been optimized, not the total package. "The connection point between these by Jack Roberts Team Feature www.jobsfor teams.com JOBS for TEAMS | 28 Filling the holes on the highway: Bottom-line boosting aerodynamics Stemco manufactures TrailerTail boat-tail aerodynamic devices.