Reducing Aerodynamic Drag

摘要

For every mile down the freeway, the average-size American car has to push 5.5 metric tons of air out of its way. that is quite literally, a drag. Overcoming this aerodynamic drag takes a lot of energy. In fact, at 70 miles (110 kilometers) per hour, the typical highway speed, as much as 65 percent of the fuel the car uses goes to overcomning air resistance. The numbers are similar for big-rig tractor-trailers, despite their far greater weight, and even higher for high-speed trains. Traveling as fast as 185 miles per hour, high-speed trains may use up to 80 percent of their fuel to overcome drag.