boundary layer
noun
: a region of fluid (such as air) moving relative to a nearby surface (such as that of an airplane wing) that is slowed by the viscosity of the fluid and its adhesion to the surface
Example Sentences
Recent Examples on the Web Two slots appear in the floor ahead of each of the belts, controlling the boundary layer that would otherwise confuse the results. 
Jonathan M. Gitlin, Ars Technica, 21 Mar. 2022 For aeroacoustic testing the rolling road is covered, and arrays of microphones set up just outside of the boundary layer. Jonathan M. Gitlin, Ars Technica, 21 Mar. 2022 In the case of airplanes, there’s a fluid boundary layer, a thin layer of air that covers any surface. Manasee Wagh, Popular Mechanics, 11 Mar. 2022 The project planned to study the Mohorovičić discontinuity, an important boundary layer between Earth's crust and mantle situated at an average depth of 49,000 feet (15,000 meters) beneath the continents. David Bressan, Forbes, 22 May 2021 The dimples produce a thin, turbulent boundary layer of air that hugs the ball's surface, decreasing the size of wake at the back of the ball. Jeff Harper, chicagotribune.com, 11 Mar. 2021 Her specialty was the field of boundary layer effects on aerospace vehicle configurations at supersonic speeds. Julia Musto, Fox News, 27 Feb. 2021 Scientists explain the increasing evening heat by pointing to the section of the atmosphere called the boundary layer, which sits just above the ground. Jane Braxton Little, Scientific American, 27 Oct. 2020 That smoke starts off in the eddies of what atmospheric scientists call the boundary layer. Matt Simon, Wired, 31 Aug. 2020 See More
Jonathan M. Gitlin, Ars Technica, 21 Mar. 2022 For aeroacoustic testing the rolling road is covered, and arrays of microphones set up just outside of the boundary layer. Jonathan M. Gitlin, Ars Technica, 21 Mar. 2022 In the case of airplanes, there’s a fluid boundary layer, a thin layer of air that covers any surface. Manasee Wagh, Popular Mechanics, 11 Mar. 2022 The project planned to study the Mohorovičić discontinuity, an important boundary layer between Earth's crust and mantle situated at an average depth of 49,000 feet (15,000 meters) beneath the continents. David Bressan, Forbes, 22 May 2021 The dimples produce a thin, turbulent boundary layer of air that hugs the ball's surface, decreasing the size of wake at the back of the ball. Jeff Harper, chicagotribune.com, 11 Mar. 2021 Her specialty was the field of boundary layer effects on aerospace vehicle configurations at supersonic speeds. Julia Musto, Fox News, 27 Feb. 2021 Scientists explain the increasing evening heat by pointing to the section of the atmosphere called the boundary layer, which sits just above the ground. Jane Braxton Little, Scientific American, 27 Oct. 2020 That smoke starts off in the eddies of what atmospheric scientists call the boundary layer. Matt Simon, Wired, 31 Aug. 2020 See More Word History
First Known Use
1921, in the meaning defined above