Experimental Investigation of the Trailer Wake Effects on the Aerodynamics of a Car Model

The aerodynamics of road vehicles has frequently been studied in simplified geometries to separate the effect of various components on aerodynamic drag and on near wake flow dynamics. In this work, the characteristics of the near wake of a Notch-Back car model were investigated, using hot-wire anemometer. The main objectives of this study are to gain a better understanding of the flow structure in the near wake region. The time-averaged and the fluctuating components of velocity were measured for the car model at various distances behind it. The effect of distance behind the car model to create maximum and minimum peaks of speed and turbulence intensity has been also investigated. Inter-model non-dimensional spacing was varied from 0.1 to 3.0, based on the lead model length. Surprisingly, significant drag increase was found for the rear model for spacing 0.1-1.3.