Wake Flows of Highly Detailed Heavy Vehicles.

This work presents a detailed wind tunnel investigation into the nature of the unsteady flow mechanisms that dictate the aerodynamic forces acting on prime-mover trailer heavy vehicles fitted with various passive flow control devices. This work builds on the current understating of the wake flow physics of heavy vehicles that until now has primarily been developed from studies utilising highly simplified geometries or time-averaged findings with realistic geometries. Unsteady base-surface and wake pressure measurements reveal how the time-averaged and unsteady flow field responds to the addition of passive aerodynamic devices that have been shown to be effective on operational heavy vehicles for improving fuel economy and reducing emissions. In comparing turbulent wake statistics and unsteady modes the time-averaged and unsteady flow response is linked directly to the measured changes in the aerodynamic drag coefficient thorough surface pressure and force measurement. The large variation in the wake structure and dynamics observed between test configurations highlights the importance of considering the detailed geometry of heavy vehicles when looking to develop advanced aerodynamic control devices that would provide benefits above and beyond those focused on in this study. [ABSTRACT FROM AUTHOR]