Nomenclature
From Thermal-FluidsPedia
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- | In order to make the symbols in the '''T'''hermal-'''F'''luids'''P'''edia consistent from all | + | In order to make the symbols in the '''T'''hermal-'''F'''luids'''P'''edia consistent from all contributors, please adhere to the following common symbols. For the symbols that are not listed below, please define them after the equations in your articles. |
==English Symbols== | ==English Symbols== |
Current revision as of 21:45, 16 December 2011
In order to make the symbols in the Thermal-FluidsPedia consistent from all contributors, please adhere to the following common symbols. For the symbols that are not listed below, please define them after the equations in your articles.
Contents |
English Symbols
Bi | Biot number, hL / k |
Bo | Bond number, |
Br | Brinkman number, |
c_{p} | specific heat at constant pressure, J/kg-K |
c_{v} | specific heat at constant volume, J/kg-K |
C | heat capacity, J/K |
C_{D} | drag coefficient |
C_{f} | friction coefficient |
D/Dt | substantial derivative |
f | degree of freedom; weight function; friction coefficient; solid fraction; wave frequency, 1/s , molecular velocity distribution function |
Fo | Fourier number, αt / L^{2} |
Fr | Froude number, or U^{2} / (gL) |
g | gravitational acceleration, m/s^{2}; specific Gibbs free energy, J/kg |
G | Gibbs free energy, J; electron-lattice coupling factor, W/m^{3}-K; irradiance, W/m^{2} |
Gr | Grashof number, gβΔTL^{3} / ν^{2} |
h | heat transfer coefficient, W/(m^{2}-K); specific enthalpy, J/kg |
latent heat of vaporization, J/kg | |
latent heat of fusion, J/kg | |
h_{sv} | latent heat of sublimation, J/kg |
H | enthalpy, J; height, m; magnetic field |
H | magnetic field vector |
I | intensity, W/m^{2}-sr; electrical current, A |
I_{0} | zeroth order modified Bessel function of the first kind |
I_{1} | first order modified Bessel function of the first kind |
I | unit tensor |
j | volume flux, m/s; superficial velocity, m/s |
J | total (diffusion + convection) flux; radiosity, W/m^{2} |
J_{0} | zeroth order Bessel function of the first kind |
J_{1} | first order Bessel function of the first kind |
Ja | Jakob number, |
k | thermal conductivity, W/(m-K) |
k | thermal conductivity tensor, W /(m-K) |
K_{0} | zeroth order modified Bessel function of the second kind |
K_{1} | first order modified Bessel function of the second kind |
k_{b} | Boltzmann constant, J/K |
K | interface curvature, 1/m; Permeability, m^{2}; dielectric constant |
K_{jk} | momentum exchange coefficient between phases j and k, kg/(m^{3}-s) |
Ka | Kapitza number, |
Kn | Knudsen number, λ / L |
L | (characteristic) length, m |
Le | Lewis number, α / D |
m | mass, kg |
M | molecular mass, kg/kmol |
Ma | Mach number,U / c; Marangoni number, |
n | unit normal vector |
N_{A} | Avogadro’s number (1/mol) |
Nu | Nusselt number, hL / k |
Nu_{x} | local Nusselt number, h_{x}x / k |
p | pressure, Pa |
Pe | Peclet number, UL / α |
Pr | Prandtl number, ν / α |
q | heat rate, W
q' || heat rate per unit length, W/m |
q" | heat flux, W/m^{2} |
q" | heat flux vector, W/m^{2} |
q"_{max} | maximum (critical) heat flux in boiling, W/m^{2} |
q"_{min} | minimum heat flux in boiling, W/m^{2} |
q"_{solar} | solar constant, 1368 W/m^{2} |
q"' | internal heat generation per unit volume, W/m^{3} |
Q | total heat transfer, J |
r | radial coordinate, m |
r | position vector m |
R | radius, m |
R_{g} | gas constant, kJ/kg-K |
Ra | Rayleigh number, gβΔTL^{3} / (να) |
Re | Reynolds number, UL / ν |
s | specific entropy, J/(kg-K) |
S | entropy, J/K |
Sc | Schmidt number, ν / D; subcooling parameter, |
Sh | Sherwood number, h_{m}L / D_{12} |
St | Stanton number, h / (ρc_{p}U) |
Ste | Stefan number, |
Sr | Strouhal number, Lf / U |
t | time, s |
T | temperature, K |
T_{m} | melting point, K |
T_{sat} | saturation temperature, K |
u | velocity in the x- direction, m/s |
U | velocity, m/s; |
v | specific volume, m^{3}/kg; velocity in the y-direction, m/s |
V | volume, m^{3} |
V | velocity vector, m/s |
w | velocity in the z-direction or axial velocity, m/s, specific work, J/kg |
W | work, J; width, m |
We | Weber number, ρU^{2}L / σ |
Wr | Womersley number, |
x | Cartesian coordinate, m; vapor quality |
X | material coordinate, m; dimensionless coordinate |
y | Cartesian coordinate, m |
Y | material coordinate, m |
Y_{0} | zeroth order Bessel function of the second kind |
Y_{1} | first order Bessel function of the second kind |
z | Cartesian coordinate, axial coordinate, m |
Z | material coordinate, m; compressibility factor, pv/RT |
Greek Symbols
α | thermal diffusivity, m2/s; relaxation factor; accommodation coefficient; wave number, void fraction; absorptivity of a surface |
β | wedge angle, rad; coefficient of thermal expansion, 1/K; contact angle measured in degrees; volumetric flow fraction |
β_{m} | composition coefficient of volume expansion |
Γ | general diffusion coefficient; liquid mass flow rate per unit width, kg/m-s |
δ | velocity boundary layer thickness, liquid or vapor film thickness, m; thermal penetration depth, m; laser irradiation penetration depth, m; thickness of the deposited film, m; thickness of surface element, m; Kronecker delta |
δ_{t} | thermal boundary layer thickness, m |
ε_{M} | momentum eddy diffusivity, m^{2}/s |
ε_{H} | thermal eddy diffusivity, m^{2}/s |
η | similarity variable, fin efficiency |
θ | inclination angle, rad; contact or wetting angle, rad; dimensionless temperature |
Θ_{n} | eigen function |
λ | mean free path, m; wavelength, m |
λ_{n} | eigenvalue |
μ | dynamic viscosity, kg/(m-s); chemical potential, J/mol; magnetic permeability |
ν | kinematic viscosity, m^{2}/s; frequency (Hz) |
ρ | density, kg/m^{3}; reflectivity of a surface |
σ | surface tension force, N/m; collision diameter, Å, Stefan-Boltzmann constant |
τ | shear stress, N/m^{2}; thermal relaxation time, s; dimensionless time,; optical thickness, m |
τ | stress tensor, N/m^{2} |
φ | Lennard-Jones potential, J; inclination angle; wave amplitude; pressure drop multiplier in two-phase flow |
ψ | stream function, m^{2}/s |
Subscripts
0 | reference variables; initial condition |
a | adiabatic, acceleration |
b | control volume face at bottom; blood; blackbody |
c | critical point, condenser, cutoff value |
cap | capillary |
CV | control volume |
E | east neighbor point |
e | equilibrium; evaporator; control volume face at east |
eff | effective value |
f | final; fuel; thin film |
g | gas (vapor); gravity |
liquid | |
L | left; characteristic length |
m | mean; melting point or mushy zone; metabolic |
men | meniscus |
N | north neighbor grid point |
n | normal to surface; control volume face at bottom |
nb | general neighbor grid points |
P | central grid point under consideration |
p | product; particle; pulse |
rad | radiation |
ref | reference frame |
S | south neighbor grid point |
s | shaft; solid; surface; control volume face at south |
sat | saturation |
T | top neighbor grid point; temperature |
t | turbulent; control volume face at top |
v | vapor phase |
W | west neighbor grid point |
w | wall; control volume face at west |
∞ | ambient or bulk property |
Superscripts
n | normal component |
t | tangential component, turbulent |
´ | fluctuation |
* | dimensionless |
+ | dimensionless |