Multi-Domain Optimization for Fuel Economy Improvement of HD Trucks 2019-01-0312
Fuel costs are significant portion of operational costs of freight owners in China. Reduction is fuel consumption for a given trip is key to increase maximize freight efficiency and increase the bottom-line of freight. In this paper, fuel economy improvements of cab over style 49T heavy duty Foton truck powered by Cummins 12 Liter engine are studied and applied systematically. In addition to finding improvements at engine level, majority of fuel efficiency improvements are also identified at vehicle level involving vehicle design (more aerodynamic), component selection/matching (low rolling resistance tires) and powertrain electronic features integration (shift schedule/electronic trims). These powertrain features include Cummins adaptive torque modulation and transmission neutral coasting. 3D CFD (ANSYS Fluent) is used to carry out aerodynamic study of truck and Cummins Vehicle Mission Simulation (VMS) is used to study powertrain integration features. Based on the baseline test on an original truck, system simulation model is developed and calibrated. Energy study indicated contribution of aerodynamic and rolling resistance losses. Powertrain integration feature are optimized using VMS tool and aerodynamic cab/ add on devices are studied using 3D CFD tool. Based on the analysis recommendation, low rolling resistance tires and aerodynamic features are applied along with electronic powertrain features on optimized truck design. Final test showed that optimized truck is about 21% better FE than baseline test. Coast-down tests and 1D system simulation indicated that low rolling resistance tires, aerodynamic design and powertrain integration features contributed 11%, 6% and 5% of fuel economy improvement, respectively.
Guoqiang (Grant) Li, Rohit Saha, Chia-Siung YU, Dan Burns, Tang Bo, Meiyou Lin
Cummins Inc., Beiqi Foton Motor Co., LTD.,