A Comparison of Full Scale Aft Cavity Drag Reduction Concepts With Equivalent Wind Tunnel Test Results 2013-01-2429
Comparison studies have been conducted on a 1:16th scale model and a full scale tractor trailer of a variety of sealed aft cavity devices as a means to develop or enhance commercial drag reduction technology for class 8 vehicles. Various base cavity geometries with pressure taps were created for the scale model. The studies confirmed that length has an important effect on performance. The interaction of the boat-tailed aft cavity with other drag reduction devices, specifically side skirts, was investigated with results showing no discernable drag performance interaction between them. Overall, the experiments show that a boat-tailed aft cavity can reduce the drag up to 13%. Full-scale tests of a commercially derived product based on these scale tests were also completed using SAE Type II testing procedures. Full-scale tests indicated a fuel savings of over 6.5%. The implementation of these devices is shown to be a viable, effective and economical way to reduce fuel consumption on ground transport vehicles.
Citation: Kehs, J., Visser, K., Grossman, J., Niemiec, J. et al., "A Comparison of Full Scale Aft Cavity Drag Reduction Concepts With Equivalent Wind Tunnel Test Results," SAE Int. J. Commer. Veh. 6(2):486-497, 2013, https://doi.org/10.4271/2013-01-2429. Download Citation
Joshua P. Kehs, Kenneth D. Visser, Jeff Grossman, Jared Niemiec, Andrew Smith, Charles M. Horrell
Clarkson University, ATDynamics
SAE 2013 Commercial Vehicle Engineering Congress
SAE International Journal of Commercial Vehicles-V122-2EJ, SAE International Journal of Commercial Vehicles-V122-2