A new study has revealed the size and shape that characterizes a "perfect fire."
The new theory identifies the height-to-base ratio that led to humans' discovery of fire, Duke University reported. The study shows the best fires are about the same tall as they are wide, with all other variables being equal. The researchers point out this is why fires have looked exactly the same since their existence was first recorded.
"Humans from all eras have been relying on this design," said Adrian Bejan, the J.A. Jones Professor of Mechanical Engineering at Duke University. "The reason is that this shape is the most efficient for air and heat flow. Our success in building fires in turn made it possible for humans to migrate and spread across the globe heat flow from fire facilitates the movement and spreading of human mass on the globe, which is a direct prediction of the Constructal Law."
In 1996, Bejan first proposed the "Contructal Law," which claims the movement of systems (such as rivers and air currents) first evolve into configuration that leads to easier access to flows. The law has been rapidly demonstrating ways to use nature as inspiration to improve the design and efficiency of man-made designs.
"Our bonfires are shaped as cones and pyramids, as tall as they are wide at the base. They look the same in all sizes, from the firewood in the chimney, to the tree logs and wooden benches in the center of the university campus after the big game. They look the same as the pile of charcoal we make to grill meat. And now we know why," Bejan said.
The findings were published in a recent edition of the journal Nature: Scientific Reports.
