The layman is more likely to consider what it costs, to move test vehicles, workshop facilities and the respective staff, to countries which have a certain climate. The manufacturers see the establishment of climatic wind tunnels as a far more efficient utilisation and giving them more independence as far as testing is concerned. The testing is then done after the necessary preparation and carried out to a timetable, almost like a production line process. In the evenings, the technicians go home and don't need to spend the nights in some hotel in Lapland.
Looking at this from a purely scientific aspect, what counts is the so called reproducability. If something had been tested yesterday, under certain conditions, it would be ideal if these environmental conditions could be exactly reproduced for the next testing. Only then would the results be really usable. How would you otherwise determine whether e.g., a particular fault, had actually been corrected?
Testing facilities of this type have been around for quite a while. The Behr company in Stuttgart, brought the first one into operation way back in 1937 (see picture 1). The requirements and demands have of course increased, making buildings the size of the one seen in picture 2 necessary. The entire upper floor is dedicated to the power-production (315 kW), the continuity and the cooling/heating of the air-flow. Only after deflection can the air-flow be directed onto the vehicle on the lower floor.
The performance data of such testing facilities is also impressive. Wind tunnels like this, can be laid out for wind-speeds from 130 to 200 km/h. For the purpose of testing the engine-cooling, a roller testbench is needed, of course two of them, for the testing of all-wheel-drive vehicles. The heat generated, must cover all occurring temperatures, also the humidity must be adjustable, e.g., up to 95 percent. At lower speeds, up to 10 mē of jet-nozzle-area are available.
Important for the testing of air-conditioners and solar-powered ventilation, is the simulation of direct sunlight in every realistic intensity and from every naturally occurring position. The probability of driving through a tunnel is also considered. Even the acoustic characteristics of air-conditioners are included in the testing. Dummies are also used (see picture 5), who, compared with their counterparts in the crash-laboratories, have a much more tranquil life. 08/13