Constants and Conversion Factors - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 381

Knudsen number Kn = λ

p / L

λ p = mean free path
L = characteristic length

Damköhler number Da = ω /( v ρ )

First Damköhler number, denotes ratio of characteristics times
of flow and chemical reaction.
ω = amount of productives by reaction a unit time a
volume.
v = flow velocity

Karlovitz number K = g u δ / u

g u = gradient of velocity
δ = thickness of preheating zone of flame front

Schmidt number Sc = ν / D

D = molar diffusivity

Lewis number Le = D / a

B.3 NOMENCLATURE

The symbols appearing in this topic are summarized in Table B.1 ; subscripts and
superscripts are listed in Table B.2 .

TABLE B.1
Meanings of Symbols

Symbol Meanings

a furnace wall area per unit length in Chapter 2, velocity gradient in Chapter 5,

and thermal diffusivity

a λ monochromatic absorptivity of spectrum λ .

a g,n the fractional amount of energy in the spectrum for the gray gas of absorption

coefficient

A nondimensional band intensity in Equation 2.22

A C area of heated surface

A H area of heating surface

A S,O , A s,P surface Damköhler numbers defined in Equation 2.40

A nh nonhomogeneous total band absorptance

A w furnace wall area, m 2 = La

b m the sum of reciprocal of the heat capacity

B line broadening parameter in Equation 2.22

B S the frequency factor of the surface reaction

c p specific heat

C half-line width in Equation 2.20

C 0 , C 1 , C 2 , C r constant

C m ·

heat capacity of object transferred by unit time

d λ monochromatic transmissivity of spectrum λ .

D line interval, diffusivity

e nondimensional line intensity in Equation 2.20