List of Symbols.
a geometrical dimension, [m]
A geometrical dimension, [m]
b geometrical dimension, [m]
B Biot number, usually hL/k.
cp specific heat, [J/kg/K]
dsi differential area element on surface Si, [m2]
$dv^{\prime }$ differential volume element, [m3]
erf (z) error function, $\func{erf}(z)=2/\sqrt{\pi }\int_{z}^{\infty}e^{-t^{2}}dt$
f boundary function, units [K] for type 1 boundary, otherwise units  [W/m2]
F(r) initial temperature distribution, [K]
g volume energy generation, $[W/m^{3}orJ/m^{3}/\sec ]$
G Green's function
h heat transfer coefficient, [W/m2/K]
H(t) Heaviside unit step function
i,j indices
J Joule, unit of energy
k thermal conductivity [W/m/K]
kg kilogram, unit of mass
K Kelvin, unit of absolute temperature
L geometrical dimension, sometimes body thickness, [m]
m fin effect parameter, [m-1]; also meter, unit of length
ni outward unit normal vector on surface Si
P propagator, function related to the GF
q heat flux, [W/m2]
r radial coordinate, [m]
$\overrightarrow{\mathbf{r}} $ position vector, [m]
R numbering system designation for radial cylindrical coordinate
RS numbering system designation for radial spherical coordinate
Si body surface
sec second, unit of time
t time, [sec]
T temperature, [K]
x,y,z Cartesian coordinates
X, Y, Z numbering system designations for Cartesian coordinates
W Watt, a unit of power, equal to one Joule per second.


Greek symbols

$\alpha $ thermal diffusivity $[m^{2}/\sec ]$
$\beta $ eigen value
$\delta (x) $ Dirac delta function
$\nabla ^{2}$ Laplacian, spatial derivative in Heat equation
$\epsilon $ small parameter
$\rho $ density [kg/m3]
$\tau $ time at which the heat pulse is released, [sec]
$\phi $ azimuthal angle, cylindrical and spherical coordinates
$\theta $ polar angle, spherical coordinates