Fuel Consumption Reductions in Heavy-Duty Vehicles With Crank Pulley Decoupler Mounted Engines

An increasing amount of effort has been directed to ensure the minimization of carbon dioxide emissions within the transport industry, particularly in the light passenger vehicle segments. This has been achieved through many advancements such as mass and aerodynamic drag reduction as well as the electrification of powertrains. The heavy-duty vehicle segment contributes significantly to the total emissions of the transport sector, however fuel consumption through electrification poses some limitations. Fuel efficiency has been achieved by adopting higher fuel injection pressures generating an increase of the crankshaft nose oscillation making Front-End Accessory Drive (FEAD) design more challenging. This paper provides a solution, with the incorporation of a crank pulley decoupler that isolates the irregularities from the FEAD that arise at the crank of the internal combustion engine. The analysis of a 12.7 L engine tested with a steel pulley and with the decoupler is presented. The brake-specific fuel consumption map is obtained for the engine mounted with the steel pulley and with the decoupler through a dynamometer test. The engine maps are incorporated into a tractor trailer with a 4 × 2 configuration in the Vehicle Energy consumption Tool (VECTO), evaluated over three driving cycles: long-haul delivery, regional delivery, and urban delivery. The outcome indicates a maximum relative fuel saving of 0.63% for a vehicle mounted with a decoupler compared to one mounted with a solid steel pulley.