3 janvier 2010
7
03
/01
/janvier
/2010
12:39
During flight, useful energy input into a system is destroyed completely in a distributed fashion by components that have equivalent functions in animals and machines. Constructal theory predicts that all flow-system structures result from the clash between two objectives: the need to carry substances from the core to the periphery and the need to avoid direct leakage of these substances and energy (such as heat) into the ambient surroundings. The ultimate purpose of food or fuel taken in by a bird or put into an airplane is to provide power for flight, which overcomes air friction and supports the mass of the animal or machine. In between fuel input and power output, however, energy is destroyed by various flow systems.
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