Summer vacations are so close one can almost smell the smoke from marshmallow-toasting campfires, bonfires on the beach, and, of course, classic backyard barbecues. What’s even better: Those imminent holiday blazes may require little thought, according to a new study.
Humans tend to build very efficient fires, perhaps unwittingly, says physicist Adrian Bejan of Duke University. And he has crunched the numbers to back up that assertion.
Across cultures, countries and eras, people have built fires by piling wood or other fuel in pyramid- or cone-shaped structures that are about as tall as they are wide at the base, Bejan says. Using back-of-the-envelope calculations of how air and heat flow through structures, he argues that fires with those proportions produce the hottest flames for their volume of fuel. Fires that are relatively tall or short compared with their width, lose more of their heat, he says.
The calculations, appearing June 8 in Scientific Reports, suggest no scout handbooks are needed for those leisurely summer blazes.
Editor’s Note: This article was updated on June 17, 2015, to correct the photo credit.