Computational Study of Drag Reduction of Models of Truck-Shaped Bodies in Ground Effect by Active Flow Control Washington Univ. St. Louis

Format:

Conference/Event

Author/Creator:

Agarwal, Agarwal, author.

Conference Name:

SAE 2013 World Congress & Exhibition (2013-04-16 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2013

Summary:

In U.S., the ground vehicles consume about 77% of all (domesticand imported) petroleum; 34% is consumed by automobiles, 25% bylight trucks and 18% by large heavy-duty trucks and trailers. Ithas been estimated that 1% increase in fuel economy can save 245million gallons of fuel/year. Furthermore, the fuel consumption byground vehicles accounts for over 70% of CO₂ and other greenhousegas (GHG) emissions in U.S. Most of the usable energy from theengine (after accounting for engine losses) at highway speed of 55mph goes into overcoming the aerodynamic drag (53%) and rollingresistance (32%); only 9% is required for auxiliary equipment and6% is used by the drivetrain. 15% reduction in aerodynamic drag athighway speed of 55 mph can result in about 5-7% in fuel saving.The goal of this paper is to demonstrate by numerical simulationson generic truck models that the active flow control (AFC)technology can be easily deployed/retrofitted to reduce theaerodynamic drag by 15-20% at highway speed. It is important tonote however that these estimates of drag reduction are based onCFD studies performed on simple generic truck models; for actualtrucks the values will be much lower because of considerablecomplexity of the configurations.For AFC, we employ a few oscillatory jet actuators (also knownas synthetic jet actuators) at the rear face of the ground vehicle.These devices are easy to incorporate into the existing vehicles atvery modest cost. The cost may come down significantly for a largevolume of actuators, especially for ground vehicles. Numericalsimulations are performed using the Unsteady Reynolds-AveragedNavier-Stokes (URANS) equations on solution adaptive structuredgrids in conjunction with a two-equation realizable k-ε turbulencemodel. The commercially available grid generator "GAMBIT"and the CFD solver "FLUENT" are employed in thesimulations. Three generic ground vehicle configurations areconsidered in the simulations; the experimental data has beenavailable for these configurations without and with AFC. Thenumerical simulations are in good agreement with the experimentaldata. In addition, a computational study is performed for one ofthe generic truck models to include the ground to evaluate itseffect on aerodynamic drag without and with AFC. These studiesclearly demonstrate that the AFC technique using synthetic jetactuators can be effectively employed to achieve significantreduction (10-15%) in aerodynamic drag with a potential of reducingthe fuel consumption by 5-7%

Notes:

Vendor supplied data

Publisher Number:

2013-01-0954

Access Restriction:

Restricted for use by site license