NOMENCLATURE
at Thermal DiffusivityA Area
Af Flow area occupied by liquid
Ag Flow area occupied by gas
Ai Internal tube surface or interfacial area
Cp Specific heat at constant pressure
Cv Specific heat at constant volume
c Sound speed
D Diameter
Dd Bubble departure diameter
Dh Hydraulic diameter
Fr Froude number
f Friction factor
G Mass velocity
Gr Grashof number
g Gravitational acceleration
h Convective heat transfer coefficient
i (or h) Specific enthalpy
ifg (or hfg) Heat of vaporization
j Volumetric flux (superficial velocity)
k Thermal conductivity
L Length
Mass flow rate
Nu Nusselt number
P Pressure
Pe Pecklet number
Pr Prandtl number
Q Volumetric flow rate
q Heat transfer rate
Re Reynolds number
r Variable radius
Ro Gas constant
R Pipe Radius
St Stanton number
s Specific entropy
T Temperature
t Time
u specific internal energy
V Velocity
Vgj Drift velocity
Vr Relative velocity
We Weber number
X Flow quality
Xeq Thermodynamic equilibrium quality
Xtt Martinelli Parameter
u,v,w Velocity components
Specific volume
dP/dz Pressure gradient
Greek Symbols
Void fraction
Difference (out-in) of X
Volumetric flow quality or thermal expansion coefficient
Film thickness
Ratio of specific heats
Interfacial mass flow rate
Wavelength
Dynamic viscosity
Wetted perimeter
Stress tensor
Shear stress
Mass density
Surface tension
Contact angle
Subscripts
d Dispersed phasee External
f Liquid phase
g Gaseous phase
i Internal or interface
m Mixture
o Stagnation value (velocity = 0)
r Relative
w Wall
cr Critical value
nb Nucleate boiling
SP Single phase
TP Two Phase
sub Subcooled
scb Subcooled boiling
sat Saturated