課程名稱︰流體力學
課程性質︰大二必修
課程教師︰馬小康
開課學院：工學院
開課系所︰機械系
考試日期（年月日）︰2008.4.25
考試時限（分鐘）：100 mins
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
(15%)(1)Write both of the conservation of mass and linear momentum equations
with the Reynolds transport theorem , and explain the difference in a
non-deforming control volume and deforming control volume for a moving
control volume .
(20%)(2)Please explain the following terms :
(a)Source
(b)Force Vortex
(c)Vorticity
(d)The relation between stream function Ψ and velocity potential Φ
(e)Angular deformation
(15%)(3)A static thrust as sketched in the following figure is to be designed
for testing a jet engine . The following conditions are known for a
typical test : Intake air velocity = 300 m/s ; exhaust gas velocity =
500 m/s ; intake cross-section area = 1 m^2 ; intake static pressure =
-22.5 kPa = 78.5 kPa(abs) ; intake temperature = 268K ; exhaust static
pressure = 0 kPa = 101 kPa(abs) . Estimate the nominal trust for which
to design .
┌───╮
│ ╰─────┐
u1 ─→│ │ u2 ──→
│ │
│ ╭──┬──┘
└─┬─╯ │
│ ─→ │
│ Fth │
────┴────┴─────
(10%)(4)A general statement of the second law of thermodynamics . Please
describe " The time rate of increase of the entropy of a system " .
(20%)(5)Five liters/s of water enter the rotor along the axis of rotation .
The cross-sectional area of each three nozzle exits normal to the
relative velocity is 18 mm^2 . How large is the resisting torque
required to hold the rotor stationary ? How fast will the rotor spin
steadily if the resisting torque is reduced to zero and θ = 30度 .
(20%)(6)A fluid flows past a circular cylinder of radius a with an upstresm
speed of Vo . A more advanced theory indicates that if viscous effects
are negligible , the velocity of the fluid along the surface of the
cylinder is given by V = Vosinθ .
(a)Determine the streamline and normal components of acceleration
(an and as)on the surface of the cylinder as a function of Vo,a,θ.
(b)When Vo = 10 m/s and a = 0.1 m ＆ 1.0 m , please plot an and as for
0度 ≦ θ ≦ 90度 .
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◆ From: 118.165.138.220
※ 編輯: steven4516 來自: 118.165.138.220 (04/26 02:11)
※ 編輯: steven4516 來自: 118.165.138.220 (04/26 02:22)