boundary layer

noun

Definition of boundary layer

: 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

Examples of boundary layer in a Sentence

Recent Examples on the Web 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, "One Climate-Change Wildfire Risk Lurks in the Dark," 27 Oct. 2020 That smoke starts off in the eddies of what atmospheric scientists call the boundary layer. Matt Simon, Wired, "A Beautiful Yet Grim Map Shows How Wildfire Smoke Spreads," 31 Aug. 2020 At Dome A, however, Earth's boundary layer is only 45.6 feet high. Popular Mechanics, "This Is the Single Best Place To Stargaze on Earth," 30 July 2020 When escaping the effects of the boundary layer, location is key. Popular Mechanics, "This Is the Single Best Place To Stargaze on Earth," 30 July 2020 That boundary layer also carries a fair amount of water vapor — evaporated perspiration. Paul Cappiello, The Courier-Journal, "Ever wonder how plants handle winter weather like wind chill? The answer? It's about water," 31 Jan. 2020 The reason for this difference is what physicists refer to as the boundary layer. Paul Cappiello, The Courier-Journal, "Ever wonder how plants handle winter weather like wind chill? The answer? It's about water," 31 Jan. 2020 This newest research also revealed that the boundary layer itself may be more complex than initially thought, with multiple layers of different temperature, density, and speed. Jennifer Leman, Popular Mechanics, "We Finally Know What Happened When Voyager 2 Reached Interstellar Space," 4 Nov. 2019 Golf ball dimples reduce the drag flow by creating a turbulent boundary layer of air, while the ball's spin generates lift by creating a higher air pressure area on the bottom of the ball than on the top. Jennifer Ouellette, Ars Technica, "Physics holds the secret to volleyball’s highly unpredictable “float serve”," 14 Nov. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'boundary layer.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of boundary layer

1921, in the meaning defined above

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Time Traveler for boundary layer

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The first known use of boundary layer was in 1921

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Last Updated

2 Nov 2020

Cite this Entry

“Boundary layer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/boundary%20layer. Accessed 3 Dec. 2020.

More from Merriam-Webster on boundary layer

Britannica.com: Encyclopedia article about boundary layer

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