DRAG REDUCTION OF A SIMPLIFIED TRUCK MODEL USING CAB ROOF FAIRINGS

Adverse effects of climate change have prompt transition towards a low-carbon transportation sector. Electrification of the transportation sector is one of the ongoing efforts to reduce the Greenhouse Gas emissions. However, electrification of long haul and heavy-duty vehicles remain a huge challenge due to cost and limitation in the current battery technology. Improving the aerodynamic design of current truck-trailer is an alternative to electrification. This initiative involves modifying the current truck-trailer body design or attaching accessories for aerodynamic drag reduction that can lead to improved fuel economy. In this paper, the effectiveness of four Cab Roof Fairing (CRF) designs on the aerodynamic drag reduction of a simplified truck model is investigated. The results of a numerical simulation performed on a two-dimensional model show that the CRF can reduce aerodynamic drag by up to 45%. The CRF is found to reduce the vertical velocity component of the flow at fore part of the truck body. This leads to a relatively smaller wake region when compared against the baseline case. Wind tunnel results is performed to verify the results of the numerical simulation. At Reynolds number , the measured coefficient of drag reduction is about 6% when compared with the baseline case.