Reduction of adverse aerodynamic effects of large trucks, Volume I. Technical report

The overall objective of this study has been to develop methods of minimizing three aerodynamic-related phenomena: truck-induced aerodynamic disturbances, splash, and spray. An analytical methodology has been developed and used to characterize aerodynamic flow, truck splash and spray generation and propagation, adjacent driver visibility factors, the performance of the disturbed adjacent driver/vehicle system, and benefit/cost comparisons. These same factors have been studied in a series of driving simulator, wind tunnel, and fullscale tests and experiments. Attention in the experiments and analyses has focused on understanding the phenomena, as well as on identifying and developing devices, techniques, and procedures for minimizing these aerodynamic effects. Several truck mounted devices and prototype concepts are identified which have the potential to alleviate the adverse effects of splash and spray in a cost-effective way. These include collector flaps, simple fenders, and aerodynamic panels and devices near the tractor, under the truck, and around the wheels. Non-vehicle means of alleviation are considered, as well. /FHWA/