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FenTrans, MecFlu, TransCal e TransMassa - Frank White - Mecânica dos Fluidos- Ed: 6º - Capítulo 7.Problemas - Ex. 53

Da Tabela 7.2, o coeficiente de arrasto de uma placa larga ao escoamento é aproximadamente 2,0. As condições do escoamento são U ∞ e p ∞ . Se a pressão média sobre a parte frontal da placa for aproximadamente igual à pressão de estagnação da corrente livre, qual será a pressão média na parte traseira?

Passo 1

E vamo lá!

Bora lá, se temos o coeficiente de atrito igual a 2,0, podemos fazer que:

F a r r a s t e = 2,0 ρ 2 U ∞ 2 A p l a c a ≈ p e s t a g n a ç ã o - p t r a s e i r a A p l a c a

Ou,

p t r a s e i r a ≈ p e s t a g n a ç ã o - ρ U ∞ 2

De Bernoulli, teremos

p e s t a g n a ç ã o = p ∞ + ρ 2 U ∞ 2

Assim, obteremos que:

p t r a s e i r a ≈ p ∞ - ρ 2 U ∞ 2

Resposta

p t r a s e i r a ≈ p ∞ - ρ 2 U ∞ 2

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