Search

The drag reduction of commercial vehicles is the principal challenge to improving fuel saving and decreasing air pollution. Accordingly, several flow control devices, including gap fairing, cab roof fairing, boat tail, and side skirt were introduced to reduce the aerodynamic drag exerted on heavy vehicles. Although such devices have exhibited good drag reduction performance, their aerodynamic performance can be improved further. Moreover, a comprehensive and systematic research is required, including drag force measurement, flow field analysis and real-scale proving ground test, to evaluate the fuel consumption of heavy vehicles. In this study, the drag reduction effect of the aero full package (AFP) of a tractor–trailer, which integrated gap fairing, flap-type side skirt and lower inclined air deflector boat tail, was investigated through wind tunnel experiments and proving ground test. On the basis of the results of drag and PIV measurement, the integrated AFP was found to significantly modify the flow structure around the vehicle, thereby leading to a 26.5% reduction in drag coefficient compared with the reference tractor-trailer model (CD = 0.693). Furthermore, the proving ground test using real tractor–trailer verified that the integrated AFP provides 13.4% fuel saving. The present results will provide practical information for improving the aerodynamic performance and fuel efficiency of heavy vehicles.

The removal of particulate matter (PM) is an important issue in public health and the global atmospheric environment. Various PM removal methods have been suggested to effectively remove PM particles. However, the effects of various factors on PM deposition are not completely clear. We quantitatively investigated the effects of flow and humidity difference in a closed chamber on PM deposition. To elucidate the parameters affecting the deposition of PM particles, PM removal efficiency and deposition constant were examined at different flow rates, flow directions, and relative humidity (RH) inside the closed system. The highest PM deposition rate was achieved under humid condition with the upward direction flow at a fan speed of RPM = 150. Mean velocity fields inside the test chamber were obtained by a particle image velocimetry (PIV) technique to quantitatively examine the effect of flow conditions on the PM deposition. The flow structure and RH inside the closed chamber have significant influence on PM deposition.