Rough Surfaces
 

https://news.google.com/news/rtc?ncl...fad7416d6c09ed

Do not know what happened, but got a double post, seems this might have been the one auto saved prior to me adding a couple of changes, looking at the time stamp. Since it was replied to, might as well go with it. Trying to figure out how to delete the other, but no success yet. Added the paragraph here that I had in the other post, and edited the prior.

Seems the same things keep getting re-invented, that is by the academics, while the real users/people/innovators, have understood such long ago, due to actual application. My old man started racing outboards in 1935-36, and has described a few of the things he/they did to get less resistance. Was common knowledge back then with boats, not to mention what has been used in the aircraft industry (to disturb airflow), obviously hydrodynamics with boats, though back then it was not necessarily about burning less fuel, and global warming, but about getting better performance, somewhat the same thing. Goes to show the difference between those that do (actually do it in real life) and those that don't (those that teach).

3M developed a film for 12M Americas Cup racers that had small oval patters on it that reduced drag and made the boats faster.

Not surprised, if you have seen some of the early racing boats, early 1900-20's, when internal combustion engines, were coming into their own and enhanced, a lot of planing surfaces were used/attempted that seem to have been re-invented in the 1950's to current day. Seems a little was lost during the depression, and ww2, obviously redirected necessities, that once again evolved for public consumption, as financial growth evolved. As is well known, steps on airplane floats are common place, and long out-date some that are attributed to bringing forth steps in off shore craft . Kinda like the direct fuel injection on many early motorcycles, that went by the wayside due to mass production cost constraints, then re-invented, but now superseded by efi. Which as far as my understanding, is nothing more than a modern carburetor, as efi mixes the fuel & air prior to induction into the cylinder, while direct port injection mixes the fuel/air in the combustion chamber itself. Not attempting to argue the benefits or detriments of any of the aforementioned, simply pointing out, that some of the so called new technology, is not really so new.