Fluids Flashcards
1
Q
Equation for
Local Friction Coefficient
A
cf = 2 · τw / ρUm²
2
Q
Equation for
Friction Drag Coefficient
A
CDF = 2 · Drag Force / Area · ρUm²
3
Q
Momentum Integral equation
A
τw = ρUm² · ∂θ/∂x
4
Q
Displacement Thickness
A
δ* = ∫(1 - U/Um) dy
5
Q
Momentum Thickness
A
θ = ∫U/Um · (1 - U/Um) dy
6
Q
Shape Factor
A
H = δ* / θ
7
Q
Equation for Vorticity (Cartesian)
A
ωz = ∂V/∂x - ∂U/∂y
8
Q
Equation for Vorticity (Cylindrical)
A
ωz = 1/r [∂/∂r (rUθ) - ∂/∂θ (Ur)]
9
Q
Continuity Equation
A
∂U/∂x + ∂V/∂y = 0
10
Q
Irrotational?
A
Vorticity = 0
∇ × u̲ = 0
11
Q
Divergence free?
A
Divergence = 0
∇ · u̲ = 0
12
Q
Stream functions
A
Constant along streamline
U = ∂ψ/∂y, V = -∂ψ/∂x
13
Q
Reynolds Number
A
Re = ρυL/μ
