neglect elevation dif max 2 2 V U V θ θ π θ Limititations 1 Steady 2 ρ constant

Neglect elevation dif max 2 2 v u v θ θ π θ

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Pressure distribution at the cylinder surface, apply Bernoully eq. (neglect elevation dif.) ,max 2 2 V U V θ θ π θ = = − = Limititations: 1. Steady 2. ρ =constant 3. frictionless flow: inviscid 4. flow along a streamline 5. gravity force 2 2 P U gz ρ + + 2 2 V P gz ρ = + + ( ) ( ) 2 2 2 2 1 1 1 4sin 2 2 P P U V U ρ ρ θ = = 2 2 1 4sin 1 2 p P P c U θ ρ = = pressure distribution on cylinder, valid for inviscid flow Cp: pressure coef. [-]
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π /2 π 0 θ 1 0 -1 -2 One side of cylinder F D : drag (force): force component parallel to the freestream flow direction : D x F dF = : cos x x D dA A F P dA θ ±²³²´ ( ) cos sin cos (projection in x-direction) sin r x y d A Rd i Rd i j dA R d dA R d θ θ θ θ θ θ θ θ = = + = = JG JG G G R y x θ r d A Rd i θ = JG JG 2 2 1 2 3 2 p p U p p U ρ ρ = = − 3 dynamic pressure units lower than p (atm. press.) r i JG
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