Volvo Trucks used SuperTruck learnings to boost efficiency, performance in 2017 powertrains; wave piston, turbocompounding, injection
Key learnings from Volvo’s SuperTruck (earlier post) efforts played a critical role in the design and engineering of Volvo Trucks North America’s recently introduced 2017 powertrain, delivering improved fuel efficiency and performance to customers. (Earlier post.)
The development of several new features, such as the wave piston, turbo compounding and a common rail fuel injection system, was supported by the SuperTruck program, sponsored by the US Department of Energy (DOE).
The US DOE SuperTruck program is a cost-shared, public-private partnership that promotes research and development to improve the freight-hauling efficiency of heavy-duty Class 8 long-haul tractor-trailer trucks. The program aims to help accelerate the development of advanced efficiency technologies that are not currently available in the market.
Volvo’s new 2017 powertrain offerings, which include new, enhanced Volvo D11 and D13 engines, turbo compounding for the D13 engine and a one-box Exhaust Aftertreatment System (EATS), feature components derived directly from the SuperTruck program.
Wave Piston. The SuperTruck program enabled extensive research of a typical combustion chamber and provided Volvo engineers the opportunity to test a new piston design. This new design added “wave” bumps on the side of the piston bowl, which allows the fuel to burn more cleanly.
The exact design of the piston was matured through tests and simulations, enabling exceptional gains in fuel efficiency, while significantly reducing soot generation. The patented wave piston, working in combination with Volvo’s other engine enhancements, delivers improved fuel efficiency of up to 2.2% for the D11 and 2.5% for the D13.
Turbo Compounding. Despite today’s efficient combustion and use of turbocharging, energy is still available in the exhaust in the form of heat and pressure. A new turbo compounding system was designed to recover this normally wasted energy on the 2017 Volvo D13 with Turbo Compound, helping boost fuel efficiency by up to 6.5%.
The SuperTruck program enabled Volvo engineers to refine the mechanics and aerodynamics of the new geartrain and turbine, ensuring peak efficiency in the “sweet spot” for Volvo’s integrated powertrain solution, which includes the I-Shift automated manual transmission and downsped engines.
Common Rail Fuel Injection System. A proven common rail fuel injection system was adapted to Volvo’s 2017 D11 and D13 engines. It enables a higher injection pressure, which improves combustion, and allows for finer control of the injection event.
Through the SuperTruck program, the fuel injection system was optimized to match the new wave piston. Extensive engine testing and simulations led to an injector with enhanced flow rate, spray angle and pressure characteristics that allow the engine to operate more quietly and burn fuel more efficiently.
The US DOE is launching SuperTruck II, an $80-million funding opportunity (DE-FOA-0001447), subject to congressional appropriations, for further research, development and demonstration of long-haul tractor-trailer truck technology.