Impact Assessment of Future Technologies for Heavy-Duty Truck, 03-R9605Printer Friendly Version
Inclusive Dates: 02/01/06 05/31/06
Background - The Environmental Protection Agency (EPA) is in the early stages of conducting the SmartWay Transport Program – a voluntary partnership to establish incentives for fuel efficiency improvements and reduction of greenhouse gas emissions. Trucking companies, especially those that deliver freight, are key partners in the SmartWay program. Under the program, they commit to measure and improve the efficiency of their trucking fleets using EPA-developed tools to quantify the benefits of different fuel-saving strategies. The SmartWay program is expected to reduce the annual production of carbon dioxide (CO2) by 33 million metric tons, nitrogen oxides (NOx) by 200,000 tons, and provide a yearly fuel savings of 150 million barrels of oil. Through discussions with the EPA, they acknowledge three vital points for the success of the SmartWay Program. Methods must be developed and implemented to: (1) prescreen potential technology improvements prior to conducting expensive vehicle tests, (2) quantify small component fuel economy improvements, and (3) optimize combinations of fuel economy improvements that provide trucking companies with the best return on investment. The Institute proposed to the EPA that SwRI use its Rapid Automotive Prototype Simulator (RAPTOR®) software to address the three-part challenge. Simulations on a representative truck from the SmartWay program using RAPTOR were used to demonstrate RAPTOR’s accuracy, flexibility, and capability.
Approach - SwRI built an analytical model of a Class 8 truck, with a fully loaded trailer, using RAPTOR. This model represents one of the trucks the EPA is using in development of the SmartWay program. The EPA authorized SwRI access to data collected during development of SmartWay driving cycles. To populate the vehicle model with accurate aerodynamic and rolling resistance data, additional coastdown testing was performed under the SmartWay program. The EPA authorized the use of a program truck and the associated data acquisition and instrumentation usage for this testing. The availability of the SmartWay data, along with existing, SwRI-owned data, was vital to the success of the project. The vehicle models were prepared, and numerous simulations were performed over a variety of SmartWay drive cycles. Simulations were run to represent a baseline, unmodified Class 8 truck, and the results were validated against EPA-collected data to demonstrate RAPTOR’s accuracy.
Accomplishments - The project results demonstrated that RAPTOR simulations could be used as a preliminary means to identify component areas where improvements in fuel economy may be found. The results show that simulations could be performed in lieu of directly performing testing as a means of ranking how effective various component modifications could be. Component modifications can be simulated alone or in combinations to quantify the effects on fuel economy. Comparisons between the actual and simulated results show SwRI's RAPTOR software to be a very accurate simulation tool.