Adrian Bejan
Adrian Bejan
Adrian Bejan is an American professor who developed modern thermodynamics and the constructal law of design and evolution in nature. He is J. A. Jones Distinguished Professor of Mechanical Engineering at Duke University and author of the new book The Physics of Life...
fish knows swimming
It was swimming that stumped us. Everyone knows that, in water, fish are weightless.
bottom channel however sides water
The water can only go up because the bottom and sides of the channel are rigid. That bulge, however undetectable, is the fish's footprint.
balance fly horizontal loss optimal run speed strike vertical
To run or fly at optimal speed is to strike a balance between the vertical and horizontal loss of energy.
running swimming illustration
The fact that the same proportionalities rule optimal running, flying and swimming is not a coincidence rather it is an illustration of the fact that a universal principle is involved. Running requires the least food when during each cycle a certain amount of work is destroyed by vertical impact and a certain amount to horizontal friction. The same balancing act is responsible for optimal flight and swimming.
two design information
Flow systems have two basic features (properties). There is the current that is flowing (for example, fluid, heat, mass, or information) and the design through which it flows.