Measurement of cross-contamination between vehicles using scalemodels

This paper deals with the problem of exhaust cross-contamination between vehicles in a slow-moving traffic queue, as would be found in a busy modern city. This study has been undertaken using an open-jet wind tunnel, to determine the level of exhaust contamination around a 1:10 scale model car under various prevailing wind conditions. Tracer-gas techniques have been combined with static pressure measurements, to model the flow of pollutants around a vehicle body. Analysis of experimental data has shown that high concentrations of pollutants are present around the front, and in the lee of a vehicle in slow moving traffic.