TRANSFER: BASICS OF MASS AND HEAT TRANSFER - Biomass as a Sustainable Energy Source for the Future - page 98

mol −1 ]

[J

E a activation energy

F view factor or configuration factor [ - ]

Fo Fourier number (defined in Table 4.1) [ - ]

m −2 ]

G incident radiation [W

s −2 ]

g gravitational acceleration [m

Gr Grashof number (defined in Table 4.1) [ - ]

m −2 ] H irradiation [W

kg −1 ]

h mass-specific enthalpy [J

m −2 K −1 ]

h heat transfer coefficient [W

kg −1 ]

h fg heat of vaporization [J

m −2 sr −1 ] I total radiative intensity [W

j D dimensionless number for mass transfer (Chilton - Colburn) [ - ]

j H dimensionless number for mass transfer (Chilton - Colburn) [ - ]

j ! i

m −2 s −1 ] species diffusive flux of species i (vector) [kg

j ! q

m −2 ] flux of energy crossing a control volume boundary [W

m −2 ]

J radiosity [W

constant in d 2 -law [m 2 s −1 ] K

s −1 ] k mass transfer coefficient [m

[s −1 ]

k reaction rate coefficient

k 0 pre-exponential factor various

L length of domain [m]

Le Lewis number (defined in Table 4.1) [ - ]

mol −1 ] MW molecular weight [kg

m mass [kg]

n real part of index of refraction [ - ]

N number of species in mixture [ - ]

N s number of surfaces bounding enclosure [ - ]

Nu Nusselt number (defined in Table 4.1) [ - ]

p pressure or partial pressure [Pa] or [bar]

Pr Prandtl number (defined in Table 4.1) [ - ]

m −2 ]

!

[W

radiative heat flux (vector)

Q heat supplied or extracted [J]

Q

heat flow supplied or extracted [W]

r radius [m]

Re Reynolds number (defined in Table 4.1) [ - ]

R SA ratio of the real surface area to the ideal surface area [ - ]

mol −1 K −1 ]

R u universal gas constant [J

s source term various

Sc Schmidt number (defined in Table 4.1) [ - ]

Sh Sherwood number (defined in Table 4.1) [ - ]

T temperature [K]

t time [s]

s −1 ] u velocity in 1D model [m

kg −1 ] u mass-specific internal energy [J

s −1 ]

!

mixture velocity (vector) [m