| Name | Field of application |
|---|
| Abbe number | optics (dispersion in optical materials) |
| Albedo | climatology, astronomy (reflectivity of surfaces or bodies) |
| Archimedes number | motion of fluids due to density differences |
| Bagnold number | flow of grain, sand, etc. Archived 2005-05-10 at the Wayback Machine |
| Biot number | surface vs. volume conductivity of solids |
| Bodenstein number | residence-time distribution |
| Bond number | capillary action driven by buoyancy Archived 2012-03-05 at the Wayback Machine |
| Brinkman number | heat transfer by conduction from the wall to a viscous fluid |
| Brownell Katz number | combination of capillary number and Bond number |
| Capillary number | fluid flow influenced by surface tension |
| Coefficient of static friction
| friction of solid bodies at rest |
| Coefficient of kinetic friction
| friction of solid bodies in translational motion |
| Colburn j factor
| dimensionless heat transfer coefficient |
| Courant-Friedrich-Levy number
| numerical solutions of hyperbolic PDEs Archived 2008-06-05 at the Wayback Machine |
| Damköhler numbers | reaction time scales vs. transport phenomena |
| Darcy friction factor | fluid flow |
| Dean number | vortices in curved ducts |
| Deborah number | rheology of viscoelastic fluids |
| Decibel | ratio of two intensities of sound |
| Drag coefficient | flow resistance |
| e | mathematics |
| Eckert number | convective heat transfer |
| Ekman number | geophysics (frictional (viscous) forces) |
| Elasticity (economics) | widely used to measure how demand or supply responds to price changes |
| Eötvös number | determination of bubble/drop shape |
| Euler number
| hydrodynamics (pressure forces vs. inertia forces) |
| Fanning friction factor | fluid flow in pipes Archived 2013-12-20 at the Wayback Machine |
| Feigenbaum constants | chaos theory (period doubling) |
| Fine structure constant | quantum electrodynamics (QED) |
| Foppl–von Karman number | thin-shell buckling |
| Fourier number | heat transfer |
| Fresnel number | slit diffraction |
| Froude number | wave and surface behaviour |
| Gain | electronics (signal output to signal input) |
| Galilei number | gravity-driven viscous flow |
| Graetz number | heat flow |
| Grashof number | free convection |
| Hatta number | adsorption enhancement due to chemical reaction |
| Hagen number | forced convection |
| Karlovitz number | turbulent combustion |
| Knudsen number | continuum approximation in fluids |
| Kt/V | medicine |
| Laplace number | free convection within immiscible fluids |
| Lewis number | ratio of mass diffusivity and thermal diffusivity |
| Lockhart-Martinelli parameter
| flow of wet gases Archived 2009-11-15 at the Wayback Machine |
| Lift coefficient | lift available from an airfoil at a given angle of attack |
| Mach number | gas dynamics |
| Magnetic Reynolds number | magnetohydrodynamics |
| Manning roughness coefficient
| open channel flow (flow driven by gravity) PDF (109 KiB) |
| Marangoni number | Marangoni flow due to thermal surface tension deviations |
| Morton number | determination of bubble/drop shape |
| Nusselt number | heat transfer with forced convection |
| Ohnesorge number | atomization of liquids, Marangoni flow |
| Péclet number | advection–diffusion problems |
| Peel number | adhesion of microstructures with substrate Archived 2005-10-26 at the Wayback Machine |
| Pi | mathematics (ratio of a circle's circumference to its diameter) |
| Poisson's ratio | elasticity (load in transverse and longitudinal direction) |
| Power factor | electronics (real power to apparent power) |
| Power number | power consumption by agitators |
| Prandtl number | forced and free convection |
| Pressure coefficient | pressure experienced at a point on an airfoil |
| Radian | measurement of angles |
| Rayleigh number | buoyancy and viscous forces in free convection |
| Refractive index | electromagnetism, optics |
| Reynolds number | flow behavior (inertia vs. viscosity) |
| Richardson number | effect of buoyancy on flow stability Archived 2015-03-02 at the Wayback Machine |
| Rockwell scale | mechanical hardness |
| Rossby number | inertial forces in geophysics |
| Schmidt number | fluid dynamics (mass transfer and diffusion) Archived 2010-01-24 at the Wayback Machine |
| Sherwood number | mass transfer with forced convection |
| Sommerfeld number | boundary lubrication Archived 2016-03-16 at the Wayback Machine |
| Stanton number | heat transfer in forced convection |
| Stefan number | heat transfer during phase change |
| Stokes number | particle dynamics |
| Strain | materials science, elasticity |
| Strouhal number | continuous and pulsating flow Archived 2009-03-25 at the Wayback Machine |
| Taylor number | rotating fluid flows |
| van 't Hoff factor | quantitative analysis (Kf and Kb) |
| Weaver flame speed number | laminar burning velocity relative to hydrogen gas Archived 2017-11-03 at the Wayback Machine |
| Weber number | multiphase flow with strongly curved surfaces |
| Weissenberg number | viscoelastic flows Archived 2006-11-01 at the Wayback Machine |
| Womersley number | continuous and pulsating flows Archived 2009-03-25 at the Wayback Machine |
