SmartTruck Systems stands behind the aerodynamic design of the UnderTray and its ability to deliver savings

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GREENVILLE, S.C. – After a disparaging report was issued by Performance Innovation Transport (PIT) claiming UnderTray systems failed to deliver fuel reduction costs, SmartTruck Systems shot back with a host of data supporting its product and its ability to deliver savings.

Mike Henderson, SmartTruck’s chief scientist and former Boeing chief of research, dispelled PIT’s report with both data from its own tests and tests conducted by an independent engineering firm.

“Our product performance is based on three legs,” said Henderson.

The first leg of testing is the Commercial Aircraft Level and Computational Design, which uses the NIS Kraken Supercomputer at the Oakridge National Laboratory to measure computational fluid dynamics (CFD).

The Kraken is the most powerful computer in the world managed by academics at the University of Tennessee.

“Small companies like us have access and are able to use these giant computers which are very complex,” said Henderson.

The test uses numerical methods and algorithms to solve and analyze problems that involve fluid flow. The high-speed supercomputer yields test results that are remarkably accurate.

Following CFD study, SmartTruck Systems submits to Accurate Coast Down Aero testing, which is based on SAE/EPA auto standard tests and modified for large trucks.

The tests are performed on the Kennedy Space Center Shuttle runway, which is one of the longest runways in the world at 18,000 ft.

“This test is the gold standard in EPA certifications,” said Henderson, who noted the rigorous protocol was modified for tractor-trailers and broken up into two tests tracking both a high speed coast down from 65 mph to 55 mph and a low speed coast down from 25 mph to a complete stop.

The third and final leg of tests included the demanding SAE J1321 Fuel Mileage testing – which was overseen and approved by an independent observer.

“This test has almost become a dinosaur in testing because it is very difficult to do,” Henderson said, noting that it is unlike the coast down test that “is very sensitive and accurate. There’s nowhere to hide, it either works or it doesn’t.”

The results from the testing confirmed the company’s belief that the UnderTray system delivers fuel efficiency and reduces emissions.

Savings in fuel consumption, according to tests, were reported between 6 and 6.3%.

“The science, technology and savings that go into our suite of aerodynamic solutions are significant, so we’re not surprised to see these results,” said Henderson. “Where the science hits the highway though is the spot where the trucking industry is able to save money. These results are right in line with not only SmartTruck’s internal testing using multiple methods, but also with what our customers are reporting out on the road—even in comparison to other aerodynamic products.”

According to Henderson, relying on a single test was not acceptable and the thorough testing leaves the chief scientist and the SmartTruck Systems approach to aerodynamics feeling confident that customers will be saving significant costs in fuel.

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  • Aerodynamic devices for the most part work by deflecting the airflow away and around the suspension I wonder long term what will happen to the wheelends with no airflow to help keep them cool.

  • Its more than just a deflection: it’s guiding the air along the path of least resistance. The wheelends and the wheels themselves are generating a HUGE amount of turbulence, and this will serve to cool the wheelends.

    If the underbody gains that much by itself, imagine how much more will be recovered with flat underbody on the trailer, and trailing edge spats on the trailer; and, atop all that, imagine how much better it will be when they get around to making the tractors truly aerodynamic.