The principal areas of influence of aerodynamics in the primary safety of road vehicles are discussed. Most obvious are cross-wind effects, arising from the aerodynamic yawing moment and from the side force. The response of cars and commercial vehicles to realistic gust profiles can be examined in a cross-wind generator, and the aerodynamic input can be measured separately in a model gust simulator or estimated either from normal wind tunnel test. In addition to the side force and yawing moment, the lift and pitching moment have been shown to have a significance influence in this case. Apart from the aerodynamic forces generated, the airflow around a vehicle also affects primary safety trough its influence on visibility (including windscreen obscuration, spray and dust cloud formation, and mud deposits) and on ventilation and noise, since these all have a bearing on the driver's performance. These aspects too can usefully be studied in wind tunnels, and reference is made to recent research work.
Abstract