유체역학기초 연습시간 #2
2017-10-23
Fluid Mechanics (9ed) Prob. 4.27
Oil flows steadily in a thin layer down an inclined plane. The velocity profile is
ρ g sin θ 
y2 
=
u
hy − 
µ 
2
Express the mass flow rate per unit width in terms of ρ, μ, g, θ, and h.
Fluid Mechanics (9ed) Prob. 4.95
Liquid falls vertically into a short horizontal rectangular open channel of width b. The total
volume flow rate, Q, is distributed uniformly over area bL. Neglect viscous effects. Obtain an
expression for h1 in terms of h2, Q, and b. Hint: Choose a control volume with outer boundary
located at x=L. Sketch the surface profile, h(x). Hint: Use a differential control volume of width
dx.
Fluid Mechanics (9ed) Prob. 4.113
A small cart that carries a single turning vane rolls on a level track. The cart mass is M = 5 kg
and its initial speed is U0 = 5 m/s. At t = 0, the vane is struck by an opposing jet of water, as
shown. Neglect any external forces due to air or rolling resistance. Determine the jet speed V
required to bring the cart to rest in (a) 1 s and (b) 2 s. In each case find the total distance traveled.