DOE Project on Heavy Vehicle Aerodynamic Drag FY 2005 Annual Report

Abstract

In Memory Dr. Sidney ('Sid') DiamondThis document is dedicated to our DOE Program Manager, supporter, and dear friend Dr. Sid Diamond. This Consortium effort would not exist without Sid's vision, dedication, perseverance, and passion. His enthusiasm for this project, with his wonderful gusto for life, was contagious and pushed our effort forward. He will be dearly missed. FY 2005 Annual Report Heavy Vehicle Systems 3 ObjectiveClass 8 tractor-trailers consume 11-12% of the total US petroleum use. At high way speeds, 65% of the energy expenditure for a Class 8 truck is in overcoming aerodynamic drag. The project objective is to improve fuel economy of Class 8 tractor-trailers by providing guidance on methods of reducing drag by at least 25%. A 25% reduction in drag would present a 12% improvement in fuel economy at highway speeds, equivalent to about 130 midsize tanker ships per year. Specific goals include:• Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles.• Establish a database of experimental, computational, and conceptual design information, and demonstrate the potential of new drag-reduction devices. Approach• Develop and demonstrate the ability to simulate and analyze aerodynamic flow around heavy truck vehicles using existing and advanced computational fluid dynamics (CFD) tools.• Through an extensive experimental effort, generate an experimental data base for code validation.• Using experimental data base, validate computations.• Provide industry with design guidance and insight into flow phenomena from experiments and computations.• Investigate aero devices (e.g., base flaps, tractor-trailer gap stabilizer, underbody skirts and wedges, blowing and acoustic devices), provide industry with conceptual designs of drag reducing devices, and demonstrate the full-scale fuel economy potential of these devices. AccomplishmentsA multi-laboratory, multi-university consortium has constructed a multi-year program plan with industry. The consortium has leveraged ASCI funds, utilized results of complimentary Laboratory, University and NASA internal supported efforts, in addition to buy-in, collaboration, and communications with truck industries and organizations. The Program has • Demonstrated several concepts and devices which meet the 25% drag reduction goal and represent a savings of 4,200 million gals per year. This is equivalent to 130 midsize tanker ships per year! • Insight from experiments and experimental data base has provided clear guidance to industry on reliable, predictable experimental techniques.• Computational results provide clear guidance and caution warnings on the use of steady Reynolds-averaged Navier Stokes (RANS) models for CFD simulations. • Address consequences with aerodynamic drag reduction and use of devices o Contouring the tractor hood reduces the grille area, also reducing coolant flow. In addition, underhood exhaust gas recirculation to meet EPA 2007 regulation requires more underhood cooling. Per industry encouragement, we are including underhood...

An experimental and computational study of the aerodynamic and passive ventilation characteristics of small livestock trailers

“…This finding is also consistent with previous studies which have shown that drag coefficients can be predicted accurately using steady RANS models but that more complex regions of the flow require careful grid resolution and/or time-dependent turbulence modelling [15,16]. It further highlights the importance of experimental validation data from which the most appropriate turbulence model for a particular geometry can be chosen.…”