Influence of Moving Ground Conditions on the Cooling Flows of Road Vehicles

To reduce fuel consumption and hence carbon dioxide emissions from road vehicles it is a necessity to reduce the amount of energy they spend during operation. One of the biggest potentials lay in the aerodynamics and in recent years road vehicles have become increasingly streamlined. However, improvements are still possible but, it requires more sophisticated simulation and experimental equipment to realize them. The introduction of moving ground systems in wind tunnels is believed to be an essential improvement to the experimental equipment. This paper explains the differences that arise in the flow field around a modern passenger car when it is being tested in stationary opposed to moving ground conditions. The study shows that moving ground conditions are essential to accurately predict the drag of the vehicle. Furthermore the moving ground condition also has a noticeable effect on the predicted massflow through the engine cooling air inlet