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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==
{|
|Bi ||  Biot number, <math>hL/k</math>
|-
|Bo ||  Bond number, <math>(\rho _\ell   - \rho _v )gL^2 /\sigma </math>
|-
|Br ||	Brinkman number, <math>\mu u_m^2 /[k(T_s  - T_c )]</math>  
|-
|''c<sub>p</sub>'' ||	specific heat at constant pressure, J/kg-K
|-
|''c<sub>v</sub>'' ||	specific heat at constant volume, J/kg-K
|-
|''C'' ||	heat capacity, J/K
|-
|''C<sub>D</sub>'' ||	drag coefficient 
|-
|''C<sub>f</sub>'' ||	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, <math>\alpha t/L^2</math>  
|-
|Fr ||	Froude number, <math>U/\sqrt {gL}</math> or <math>U^2 /(gL)</math>  
|-
|''g''  ||	gravitational acceleration, m/s<sup>2</sup>; specific Gibbs free energy, J/kg 
|-
|''G'' ||	Gibbs free energy, J; electron-lattice coupling factor, W/m<sup>3</sup>-K; irradiance, W/m<sup>2</sup>
|-
|Gr ||	Grashof number, <math>g\beta \Delta TL^3 /\nu ^2 </math>  
|-
|''h'' ||	heat transfer coefficient, W/(m<sup>2</sup>-K); specific enthalpy, J/kg 
|-
|<math>h_{\ell v}</math> ||	latent heat of vaporization,  J/kg 
|-
|<math>h_{s\ell }</math> ||	latent heat of fusion, J/kg
|-
|<math>h_{sv }</math> ||	latent heat of sublimation, J/kg
|-
|''H'' ||	enthalpy, J; height, m; magnetic field
|-
|'''H''' || magnetic field vector
|-
|''I'' ||	intensity, W/m<sup>2</sup>-sr; electrical current, A
|-
|''I<sub>0</sub>'' ||	zeroth order modified Bessel function of the first kind
|-
|''I<sub>1</sub>'' ||	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<sup>2</sup>
|-
|''J<sub>0</sub>'' ||	zeroth order Bessel function of the first kind
|-
|''J<sub>1</sub>'' ||	first order Bessel function of the first kind 
|-
|Ja ||	Jakob number, <math>c_p \Delta T/h_{\ell v}</math>  
|-
|''k'' ||	thermal conductivity, W/(m-K)
|-
|'''k''' ||	thermal conductivity tensor, W /(m-K)
|-
|''K<sub>0</sub>'' ||	zeroth order modified Bessel function of the second kind
|-
|''K<sub>1</sub>'' ||	first order modified Bessel function of the second kind
|-
|''k<sub>b</sub>'' ||	Boltzmann constant, J/K
|-
|''K'' ||	interface curvature, 1/m; Permeability, m<sup>2</sup>; dielectric constant
|-
|''K<sub>jk</sub>'' || momentum exchange coefficient between phases j and k, kg/(m<sup>3</sup>-s)
|-
|Ka || Kapitza number, <math>\mu _\ell ^4 g/[\left( {\rho _\ell   - \rho _v } \right)\sigma ^3 ]</math> 
|-
|Kn ||	Knudsen number, <math>\lambda /L</math> 
|-
|''L'' ||	(characteristic) length, m 
|-
|Le || Lewis number, <math>\alpha /D</math>  
|-
|''m'' ||	mass, kg
|-
|''M'' ||	molecular mass, kg/kmol 
|-
|Ma ||	Mach number,<math>U/c</math>; Marangoni number, <math>\left( {dT/dy} \right)\left( {d\sigma /dT} \right)\delta ^2 /\left( {\alpha _\ell  \mu _\ell  } \right)</math>
|-
|'''n'''  || unit normal vector 
|-
|''N<sub>A</sub>''||	Avogadro’s number (1/mol) 
|-
|Nu || Nusselt number, <math>hL/k</math>   
|-
|Nu<sub>x</sub>  || local Nusselt number, <math>h_x x/k</math> 
|-
|''p'' || 	pressure, Pa 
|-
|Pe ||	Peclet number,  <math>UL/\alpha</math>
|-
|Pr ||	Prandtl number, <math>\nu /\alpha</math> 
|-
|''q'' || 	heat rate, W 
''q''' || 	heat rate per unit length, W/m 
|-
|''q"'' ||	heat flux, W/m<sup>2</sup>
|-
|'''q"''' ||	heat flux vector, W/m<sup>2</sup> 
|-
|''q"<sub>max</sub>'' || maximum (critical) heat flux in boiling, W/m<sup>2</sup>  
|-
|''q"<sub>min</sub>'' || minimum heat flux in boiling, W/m<sup>2</sup> 
|-
|''q"<sub>solar</sub>'' || 	solar constant, 1368 W/m<sup>2</sup> 
|-
|''q"'''|| 	internal heat generation per unit volume, W/m<sup>3</sup>
|-
|''Q'' ||	total heat transfer, J
|-
|''r'' ||	radial coordinate, m 
|-
|'''r''' ||	position vector m
|-
|R ||	radius, m
|-
|R<sub>g</sub> ||	gas constant, kJ/kg-K
|-
|Ra ||	Rayleigh number, <math>g\beta \Delta TL^3 /(\nu \alpha )</math>  
|-
|Re ||	Reynolds number, <math>UL/\nu</math> 
|-
|''s'' ||	specific entropy, J/(kg-K)
|-
|''S'' ||	entropy, J/K 
|-
|Sc ||	Schmidt number, <math>\nu /D</math>; subcooling parameter, <math>c_{ps} (T_m  - T_i )/h_{s\ell }</math>   
|-
|Sh ||	Sherwood number, <math>h_m L/D_{12}</math>  
|-
|St ||	Stanton number, <math>h/(\rho c_p U)</math> 
|-
|Ste ||	Stefan number, <math>c_p \left| {T_w  - T_m } \right|/h_{s\ell }</math> 
|-
|Sr ||	Strouhal number, <math>Lf/U</math>  
|-
|''t'' ||	time, s 
|-
|''T'' ||	temperature, K 
|-
|''T<sub>m</sub>'' ||	melting point, K 
|-
|''T<sub>sat</sub>'' ||	saturation temperature, K 
|-
|''u'' ||	velocity in the x- direction, m/s 
|-
|''U'' ||	velocity, m/s; 
|-
|''v'' || 	specific volume, m<sup>3</sup>/kg; velocity in the y-direction, m/s
|-
|''V'' || volume, m<sup>3</sup>
|-
|'''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, <math>\rho U^2 L/\sigma </math>
|-
|Wr ||	Womersley number, <math>\sqrt {\omega R^2 /\nu }</math>
|-
|''x'' ||	Cartesian coordinate, m; vapor quality
|-
|''X'' ||	material coordinate, m; dimensionless coordinate 
|-
|''y'' ||	Cartesian coordinate, m 
|-
|''Y'' ||	material coordinate, m
|-
|''Y<sub>0</sub>'' ||	zeroth order Bessel function of the second kind
|-
|''Y<sub>1</sub>'' ||	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<sub>m</sub> ||	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<sub>t</sub> ||	thermal boundary layer thickness, m
|-
|ε<sub>M</sub> ||	momentum eddy diffusivity, m<sup>2</sup>/s
|-
|ε<sub>H</sub> || thermal eddy diffusivity, m<sup>2</sup>/s
|-
|η ||  	similarity variable, fin efficiency
|-
|θ || 	inclination angle, rad; contact or wetting angle, rad; dimensionless temperature
|-
|Θ<sub>n</sub> || 	eigen function 
|-
|λ ||	mean free path, m; wavelength, m
|-
|λ<sub>n</sub> || 	eigenvalue
|-
|μ ||	dynamic viscosity, kg/(m-s); chemical potential, J/mol; magnetic permeability 
|-
|ν ||	kinematic viscosity, m<sup>2</sup>/s; frequency (Hz)   
|-
|ρ ||	density, kg/m<sup>3</sup>; reflectivity of a surface
|-
|σ ||	surface tension force, N/m; collision diameter, Å, Stefan-Boltzmann constant   
|-
|τ || 	shear stress, N/m<sup>2</sup>; thermal relaxation time, s; dimensionless time,; optical thickness, m
|-
|'''τ''' || 	stress tensor, N/m<sup>2</sup>
|-
|φ || 	Lennard-Jones potential, J; inclination angle; wave amplitude; pressure drop multiplier in two-phase flow
|-
|ψ || 	stream function, m<sup>2</sup>/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
|-
|<math>\ell</math> ||	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
|-
|<nowiki>+</nowiki>||dimensionless
|-
|}

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