One of these days as you're traveling down the interstate, don't be surprised if you see a Class 8 (18-wheeler) truck that looks more like a low-flying airplane than the familiar big rig.
A perfect storm of factors is providing the impetus to revolutionize truck design, including high fuel costs, heightened environmental awareness, and mandates from state and federal agencies to boost fuel efficiency and reduce carbon emissions. Today's trucks average only 6 mpg or less and add a whopping 423 million pounds of CO2 to the atmosphere every year. That is no longer acceptable.
Not surprisingly, California is leading the way in pioneering environmental initiatives that impact the trucking industry. The new California Air Resource Board (CARB) regulations mandate a minimum mileage improvement of 5 percent for long-haul trucks operating within the state's borders.
For truck owners, CARB is a headache. For BMI Corporation, an engineering services firm based in Greenville, South Carolina, and its sister firm SmartTruck Brands, the new rules are a golden opportunity. Says Mike Henderson, CEO and founder of BMI, "CARB and the other regulatory rules impacting the trucking industry are opening up an entirely new market for us."
Before founding BMI, Henderson was a 30-year veteran of the Boeing Company. He and his team of engineers are specialists in the design of aerodynamically advanced aircraft as well as racing and motorsports vehicles. That experience includes the use of advanced modeling and simulation techniques made possible by CFD (computational fluid dynamics) software running on high performance computers (HPC) — a set of skills that they are now applying to the problem of making Class 8 trucks more fuel-efficient and less polluting.
Retrofitting What's Already on the Road
BMI took both a short-term and a long-term approach to complying with present and future mandates. First, given the impending CARB regulations, completely redesigning the long-haul trucks from the tires up was not an option. Instead they needed an economical and efficient solution that could be applied to trucks already on the road. Then they could turn their attention to a "clean sheet" design of the truck of the future. BMI's answer to its immediate need was to launch the Smart Truck program.
"Our first goal is to design add-on parts for existing trucks to make them more aerodynamic," Henderson says. "By reducing drag, we boost fuel efficiency and cut the amount of carbon that's being dumped into the environment. Once we have the existing fleets retrofitted, we can turn our attention to creating a brand new, highly aerodynamic vehicle with optimum fuel efficiency."
A Class 8 truck (aka tractor–trailer) consists of two parts: the tractor, a motorized vehicle, is used to tow the trailer, a larger container unit without an engine, front wheels, or front axle. Combined, the two units are called an 18-wheeler, referring to the truck's total number of tires.
Initially, the BMI team used an HPC cluster to model drag-reducing parts for the trailer by simulating the action of complex airflows over and around a typical unit. The team used a conventional HPC cluster with a limited number of computing cores — and they were not happy with the results.
"On the conventional cluster we had to simplify the problem," Henderson explains. "We couldn't handle the really complex models — the solutions lacked accuracy. We could explore possibilities, but we couldn't run the detailed simulations needed to verify that the designs were meeting our fuel efficiency goals."
BMI was, as they say in computer industry jargon, compute-bound. Its engineers needed orders-of-magnitude additional computing capability, both to run highly detailed, accurate models of the trailer retrofit components and to get the results in time to meet the looming CARB deadlines.
Thanks to Jaguar, that capability was delivered just in time, essentially allowing BMI to complete the modeling phase of the Smart Truck project approximately ten times faster than otherwise possible. Overall, the company initially projected a more than 3 year concept-to-manufacture window, says Henderson; but with Jaguar's raw computing power, that critical timeframe was reduced to 18 months. And, he adds, BMI believes it achieved a higher-quality product as well.
Hunting a Jaguar
At the recommendation of some aerospace colleagues, BMI approached the Oak Ridge Leadership Computing Facility at the Department of Energy's (DOE) Oak Ridge National Laboratory in Tennessee. Through the laboratory's Industrial HPC Partnerships Program, BMI applied for, and received, access to the extraordinary computational capabilities of the Jaguar HPC.
Jaguar is DOE's flagship supercomputer. With a quarter of a million processing cores and a theoretical peak computational capability of 2.3 petaflops, BMI was able to tap into all the computational power it needed. (A petaflop, a measure of a computer's processing speed, refers to a thousand trillion [one quadrillion] floating point operations per second.) In addition, BMI opted to run the FUN3D application, NASA's CFD software that is used widely in the aerospace industry.
Access to Jaguar allowed BMI to design a unique UnderTray system, a group of aerodynamic add-on parts that minimizes drag associated with the trailer's underside components. The Under Tray system compresses and accelerates incoming airflow, as well as injecting high-energy incoming air and associated airflow from the top of the trailer down into the trailer's wake.
On the smaller HPC clusters that BMI was using before moving to Jaguar, running a model of a typical UnderTray component might take four days and use every resource the cluster had to offer. Jaguar allows the BMI engineers to break the truck into literally hundreds of pieces in order to calculate drag with a high degree of accuracy.
Says John Anastos, BMI project engineer, "Breaking the model down into that many pieces and resolving the flow on each one is something you can't do with a small cluster — it would take weeks to get a solution. But with Jaguar we can do whatever we want in terms of complexity and still get reasonable results that allow us to turn the design around in hours instead of days. All we leave out are the nuts and bolts — every other detail is represented in the computer."
BMI Trailer UnderTray System simulation
Design Digitally, Confirm Physically
Access to Jaguar led BMI to the Holy Grail many manufacturers seek: the ability to substantially reduce or completely bypass the costly and time-consuming process of creating multiple physical prototypes in the design phase of new product development.
Comments Henderson, "Developing these parts through physical experimentation is a real exercise in frustration, which is one reason it hasn't been done. It's extremely expensive and you don't learn as much—you can't see the flow and take it apart like you can with a CFD solution. So we develop our designs computationally, and then confirm them physically through testing to be sure we haven't overlooked a problem. With the speed and power of Jaguar we were able to create and evaluate the most complex model of a trailer to date and dramatically accelerate that design process."
The approach worked. Access to Jaguar permitted BMI to run models approximately ten times faster than is possible on their internal systems. And when it came to correlating the computer-generated simulations with physical tests in the field, the BMI team scored an A+. The team's test truck, loaded with prototype components and telemetry, was put through its paces on the world's longest, smoothest concrete landing strip—the 18,000-foot runway at the Kennedy Space Center. These tests confirmed the accuracy of the CFD simulations and the operational efficiency of the new add-on component designs based on those simulations.
"We were pleased to see how closely our CFD simulations match the physical test results," says Henderson. "The process works — physical test results were within one percent of our CFD calculations. And we were able to pass Environmental Protection Agency fuel tests on the first try — something almost unheard of in our industry. Without Oak Ridge and Jaguar, it would be impossible to be where we are today."
The EPA SmartWays program has certified the UnderTray system components with a 6.8 percent fuel savings, designating them as CARB-compliant for use in California. This goal was reached with a minimum package; a full set of UnderTray components provides nearly a 12 percent savings. If all of the 1.3 million Class 8 trucks in the country were configured with just the minimum package of new components, the United States could annually save almost 1.5 billion gallons of diesel fuel, reduce CO2 emissions by 32.7 billion pounds (16.4 million tons), and save $4.42 billion in fuel costs.
Launching an Industry
In the highly competitive industrial world, cool designs matter only if they generate hard cash. The power of Jaguar has allowed BMI to use its aerospace and racecar design expertise to turn leading-edge aerodynamic designs into market-ready, retrofittable products for the trucking industry. And they were able to do it at an unprecedented pace. By bringing products to market faster, BMI and SmartTruck Brands will realize revenue earlier and move into a leadership position in a new industry. With this early-to-market advantage, the companies should capture even greater market share, increasing their revenue opportunity.
However, the positive economic impact extends beyond BMI and SmartTruck Brands. The parts for the Smart Truck retrofits are being manufactured in Georgia by Cellofoam, and the various metal hardware components, such as screws and brackets, are being manufactured by a variety of metal companies in South Carolina. In today's stressed economic environment, the addition of any type of domestic manufacturing is beneficial to both the region and the country as a whole, providing economic stimulus at the local and national levels.
Market receptivity has been positive and quick. Heavy Duty Trucking magazine, a leading industry publication, named the new UnderTray system one of the top 20 products of the year. And the first production UnderTray products are being installed on fleets owned by BMI/SmartTruck Brands customers Frito-Lay, Swift Transportation, and Conway Truckload, permitting their fleets to move products into and throughout California. The company has embarked on the next phase of its truck retrofitting program with the design of a new aerodynamic trailer configuration and fuel-efficient modifications to existing tractors.
At the same time, BMI and SmartTruck Brands are taking the first steps toward their long-term goal: the design of a highly aerodynamic truck from the ground up — an ambitious "clean sheet" project. In the not too distant future, this work will culminate in the creation of "Super Truck," a futuristic vehicle with astonishing fuel efficiency that may bear little resemblance to the classic big rigs currently on the road.
Reprinted with permission of Oak Ridge National Laboratory