Another April, another SAE World Congress Experience—the organization’s flagship event (wcx18.org). A time when global mobility experts descend on Cobo Hall in Detroit to share insights and innovations on any and every conceivable topic related to automotive engineering. A notable example, the Connect2Car track (www.sae.org/attend/connect2car-wcx/attend) covers pressing issues related to automated driving, smart cities, cybersecurity, regulatory developments and policies—and Kirigami optics. This program takes on more immediacy, certainly, following the recent fatal collision in Arizona involving an Uber autonomous vehicle and a pedestrian (www.sae.org/news/2018/03/uber-fatality-accident).
As past participants and attendees know full well, WCX is not strictly an automotive event. Connect2Car is just as relevant to heavy trucks as it is passenger vehicles. Engineers and executives who develop commercial vehicles, off-highway and military machines, as well as the critical systems and components that drive them, present their technical know-how alongside that of their automotive colleagues.
Take for example, SAE’s High-Efficiency IC Engine Symposium (www.sae.org/attend/high-efficiency/attend), which precedes WCX on April 8-9, at the Westin Book-Cadillac Hotel that’s within easy walking distance of Cobo. A session on “Advanced Heavy-duty Concepts” sees experts from Southwest Research Institute (SwRI) and Volvo Global Trucks Technology presenting on high-efficiency engines for long-haul trucks and the impact of emissions regulation on technology development.
Organic Rankine cycle-based waste heat recovery (WHR) systems have been developed to a near production-ready state, but still suffer from a poor cost/benefit tradeoff, according to SwRI’s Tom Briggs, one of the presenters. One promising path to dramatically increase the efficiency of WHR—increasing the power output while maintaining or reducing system cost—is to transition to a supercritical CO2 system. The thermodynamic properties of supercritical CO2 are “ideally suited” to WHR on a heavy-duty engine, and cycle analysis suggests that a realized system could have twice the efficiency of an organic Rankine cycle, the session program teases.
At WCX proper, advanced propulsion/powertrain sessions devoted to heavy-duty dot the event program. “Advances in NOx Reduction Technology” will be of high interest, particularly with ultra-low NOx emissions standards for heavy trucks looming. Also of note is a technical expert panel discussion, on April 10, titled “Medium-Duty and Heavy-Duty Vehicle Efficiency Opportunities through the Co-Optimization of Fuel and Engine Technologies.” Topics covered will include conventional mixing controlled combustion, advanced kinetically controlled combustion strategies, and potential synergies with electrification of vehicle powertrains.
Platooning is another hot topic at WCX. Lawrence Livermore National Laboratory researchers present results of a series of scaled wind-tunnel tests to investigate the aerodynamic benefits of heavy-vehicle platooning. LLNL designed and fabricated a wind-tunnel platform to test truck platoons up to three vehicle configurations with separation distances between 5 and 320 ft (1.5 and 97.5 m) full-scale. The platform accounts for crosswind effects on the drag force and cooling air supply for yaw angles ranging from -15 to 15 degrees.
Similarly, researchers at Auburn University and the U.S. Army focused on more complex platoon configurations for their CFD and high-fidelity truck simulations. Though the four-vehicle platoon featured two M915s and two Peterbilt 579s with dissimilar trailer configurations, the result on fuel savings was still positive.
And Volvo Group, with the help of several research organizations, evaluated cooperative adaptive cruise control (CACC), using wireless vehicle-vehicle communication to augment radar sensor data, on a three-truck platoon on a closed test track. Inter-vehicle gaps ranged from 3.0 seconds or 87 m (285 ft) to 0.14 seconds or 4 m (13 ft). The middle truck saved the most fuel at gaps shorter than 12 m (39 ft) and the trailing truck saved the most at longer gaps, while lead truck saved the least at all gaps.
Scanning the tech-session speaker lineup reveals a host of other familiar names: Caterpillar Inc., CNH Industrial, Cummins, Eaton, Hino Motors, John Deere Power Systems, Navistar, TARDEC—a veritable Who’s Who of the heavy on- and off-highway worlds.Continue reading »