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WikiCards · Card list · Science cards · Boundary layer
Uncommon card · Science
Boundary layer, an Uncommon card
In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a bounding surface formed by the fluid flowing along the surface.
- Rarity
- Uncommon
- Domain
- Science
- ATK
- 76
- DEF
- 65
- Power
- 141
- Wikipedia reads a year
- 50,000
Power 141 (ATK + DEF): stronger than 75 % of WikiCards cards.
Boundary layer quiz: 3 questions
Three questions on the Boundary layer card, the way WikiCards duels ask them. Pick an answer, the facts are just below.
Find the missing word
The fluid's ______ with the wall induces a no-slip boundary condition.
Answer
interaction. The fluid's interaction with the wall induces a no-slip boundary condition. From the Boundary layer article on Wikipedia.
Which of these Wikipedia articles is read the most in a year?
Answer
Apatite. Apatite 78,000 · Boundary layer 50,000 · Aluminium recycling 18,000 · Ashok Seth 11,000 Wikipedia reads over a year.
In a duel, each round asks a question like these about the opposing card, with 15 seconds to answer.
The facts on the card
The card carries these facts from its Wikipedia article.
- The fluid's interaction with the wall induces a no-slip boundary condition.
- The flow velocity then monotonically increases above the surface until it returns to the bulk flow velocity.
- The thin layer consisting of fluid whose velocity has not yet returned to the bulk flow velocity is called the velocity boundary layer.
Why it is Uncommon
Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Boundary layer article was read about 50,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 76 and blocks with 65: each hit it takes is cut by 26 %.
How to get Boundary layer
Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.
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The cards just above and just below Boundary layer in the power ranking, all domains together.
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- Qinghai LakeUncommon · Nature · ATK 69 DEF 72
- Military engineeringUncommon · History · ATK 73 DEF 68
- Maritime transportUncommon · Society · ATK 75 DEF 66
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Credits
Text : Wikipedia, Boundary layer (revision), CC BY-SA 4.0. Photo : Gary Settles, CC BY-SA 3.0, Wikimedia Commons.
