A sub-scale investigation of automobile drag and lift interference in a 3/4- open jet wind tunnel

The motivation for this study comes from the fact that aerodynamic interference is present in all wind tunnels. Here, aerodynamic "interference" is taken to be the deviation between the true result—which can only be estimated—and the actual result obtained from the wind tunnel. Because interference effects give rise to errors in wind tunnel simulation, they are an impediment to aerodynamic correlation of any new wind tunnel. Correction methods for interference effects have been most thoroughly investigated and, as a result, are best understood for solid wall test sections. Unfortunately, solid wall wind tunnels devoted to full-scale automotive testing have to be very large (test section areas of approximately 500 ft² or larger) to hold the simulation error to correctable levels. For open jet test sections, which have traditionally been the choice of the European community for aerodynamic testing, interference effects have never truly been quantified. Only in recent years have open jet test sections become a popular choice for aerodynamic test facilities in North America. The cumulative result is that open jet aerodynamic interference is poorly understood.