Mechanisms of Particle Deposition - Aerosols: Measurement, Dosimetry, and Health Effects - page 68

μ
ρ g

ν = kinematic air viscosity (cm 2 ·s −1 ) at STP, ν = 1.52 × 10 −1 cm 2 ·s −1

λ mean free path of air (cm) at STP, λ = 6.5 × 10 −6 cm

V a mean velocity of air in an airway (cm·s −1 )

Deposition Eficiencies

P ( I ) deposition eficiency for inertial impaction fraction

P ( S ) deposition eficiency for sedimentation fraction

P ( D ) deposition eficiency for diffusion fraction

P ( Int ) deposition eficiency for interception fraction

Dimensionless Parameters

ρ dV = Reynolds number

Re

μ

2λ
d p

Kn = Knudsen number

1 2 /

d
R

⎛
⎜

⎞
⎟

De = Dean number

Re

2

Fiber Characteristics

L f iber length (μm)

- f mean length of iber projection into the plane normal to the airway axis (μm)

d f iber diameter (μm)

Particle Cloud Characteristics

d c cloud terminal diameter (cm)

V c cloud terminal settling velocity (cm·s −1 )

ρ V d = cloud Reynolds number (dimensionless)

Re c

a c c

μ

ρ c mass concentration of particles in a cloud (g·cm −3 )

Airway Properties

L a airway length (cm)

d a airway diameter (cm)

r a airway radius (cm)

θ b airway branching angle (°)

Other Quantities

k Boltzmann's constant

k = 1.38 × 10 −16 g·cm 2 ·s −2 ·molecule −1 ·K −1

T absolute temperature (Kelvin)

g gravitational acceleration rate

g = 9.8 × 10 2 cm·s −2