This article is a great example of NIH syndrome.<p>You can get the same improvement with "About $5 of materials and an hour of time." [1]<p>That's by Dale Andreatta, a mechanical engineer that's been tinkering with improved stoves for decades. But he's not the only one, there are plenty of pot tweaks that achieve comparable or better the the improvements cites in the article.<p>Like many commenters below bring up, there are other design constraints to cooking technology than raw throughput -- performance at low temperature, manufacturing complexity, ease of cleaning, evenness of heating, performance under varying ambient conditions (humidity, wind, temp).<p>I encountered many such rocket scientists (literally) while designing improved stoves over the last few years. The engineering of stoves only superficially resembles the engineering of jet engines: the quantities are all different (low flow rate, low pressures, lower temperatures) and, as a result, the overall drivers of performance are very different (for example, stove to pot efficiency is largely governed by excess air control, NOT surface area)<p>A good example is that I got many recommendations to add "swirlers" [2] to stoves to improve mixing and reduce output CO. This works great in a jet, but it's useless in a stove: there's not enough pressure generated by natural draft to make the device effective.<p>[1] pg. 14
<a href="http://www.vrac.iastate.edu/ethos/files/ethos2008/Sat%20AM%20Classroom%201/Andreatta%20A%20Study%20of%20Heat%20Transfer%20in%20Finned%20Pots.pdf" rel="nofollow">http://www.vrac.iastate.edu/ethos/files/ethos2008/Sat%20AM%2...</a><p>[2]
<a href="https://www.google.com/search?q=swirlers+jet+engine&espv=2&tbm=isch&tbo=u&source=univ&sa=X&ei=DgnDU6v9CozqoATUxYHgAw&ved=0CDcQsAQ&biw=1460&bih=1148" rel="nofollow">https://www.google.com/search?q=swirlers+jet+engine&espv=2&t...</a>