Understanding how aerodynamics affects your rig.
When you’re towing a bluff, full-size caravan around, aerodynamics seems to be the least of your worries. With the drag of an extra set of wheels or two to pull along and, of course, the extra weight involved, it would appear that high fuel consumption goes with the territory for caravanners.
Yet, nothing could be further from the truth. Knowing about basic aerodynamics and how they affect your rig is really important, not only for fuel consumption, but also for wear on your tow tug, and the stability and safety of the rig as a whole.
Automotive engineers became interested in aerodynamics and their effect on vehicles in the early-to-mid 1900s, as cars became a regular feature in society and their ability to travel at speed increased. Engineers began work on the most efficient shape for a car body, which was found to be a teardrop shape. An early example of such a car is the 1921 Rumpler Tropfen-auto, with a low aerodynamic coefficient of drag (Cd) figure of .27, as good as the better cars of today.
The teardrop shape didn’t exactly take off, so the cars through the ages that have been commercially accepted are also a more conventional shape. Such cars include the 1935 Chrysler Airflow and 1955 Citroen ID/DS series.
Later on, detail improvements became important