Categories: Dimensionless numbers | Fluid mechanics | Convection In fluid mechanics, the Reynolds number is the ratio of inertial forces (vsρ) to viscous forces (μ/L) and consequently it quantifies the relative importance of these two types of forces for given flow conditions. ... In physics, the Péclet number is a dimensionless number relating the forced convection of a system to its heat conduction. ... The Nusselt number is a dimensionless number which measures the enhancement of heat transfer from a surface which occurs in a real situation, compared to the heat transfer that would be measured if only conduction could occur. ... In the physical sciences, a dimensionless number (or more precisely, a number with the dimensions of 1) is a quantity which describes a certain physical system and which is a pure number without any physical units; it does not change if one alters ones system of units of measurement... Fluid dynamics is the sub-discipline of fluid mechanics dealing with fluids (liquids and gases) in motion. ... An Archimedes number, named after the ancient Greek scientist Archimedes, to determine the motion of fluids due to density differences, is a dimensionless number in the form where: g = gravitational acceleration (9. ... The Bagnold number, named after Ralph Alger Bagnold, used in granular flow calculations, is defined by where is the mass, is the grain diameter, is the surface tension and is the interstitial fluid viscosity. ... In fluid mechanics, the Bond number expresses the ratio of gravitational forces to surface tension forces: where is the density, the acceleration due to gravity, a representative length scale (typically the radius of a drop), and the strength of the surface tension. ... The Brinkman Number is a dimensionless group related to heat conduction from a wall to a flowing viscous fluid, commonly used in polymer processing. ... The capillary number represents the relative effect of viscous forces and surface tension acting across an interface between a liquid and a gas, or between two immiscible liquids. ... The Damköhler numbers (Da) are dimensionless numbers used in chemical engineering to relate chemical reaction timescale to other phenomena occurring in a system. ... The Deborah number is a dimensionless number, used in rheology to characterize how fluid a material is. ... The Eckert number is a dimensionless number used in flow calculations. ... The Ekman number, named for V. Walfrid Ekman, is a dimensionless number used in describing geophysical phenomena in the oceans and atmosphere. ... The Euler number or cavitation number is a dimensionless number used in flow calculations. ... The Froude number is a dimensionless number used to quantify the resistance of an object moving through water, and compare objects of different sizes. ... This article or section does not cite its references or sources. ... The Grashof number is a dimensionless number in fluid dynamics which approximates the ratio of the buoyancy force to the viscous force acting on a fluid. ... The Hagen number is a dimensionless number used in forced flow calculations. ... The Knudsen number (Kn) is the ratio of the molecular mean free path length to a representative physical length scale. ... The Laplace number (La) is a dimensionless number used in the characterisation of free surface fluid dynamics. ... The Lewis number is a dimensionless number approximating the ratio of mass diffusivity and thermal diffusivity, and is used to characterize fluid flows in where there are simultaneous heat and mass transfer by convection. ... An F/A-18 Hornet breaking the sound barrier. ... The Marangoni number (Mg) is a dimensionless number named after Italian scientist Carlo Marangoni. ... The Nusselt number is a dimensionless number which measures the enhancement of heat transfer from a surface which occurs in a real situation, compared to the heat transfer that would be measured if only conduction could occur. ... The Ohnesorge number, Z , is a dimensionless number that relates the viscous and surface tension force. ... In physics, the Péclet number is a dimensionless number relating the forced convection of a system to its heat conduction. ... The Prandtl Number is a dimensionless number approximating the ratio of momentum diffusivity and thermal diffusivity. ... In fluid mechanics, the Reynolds number is the ratio of inertial forces (vsρ) to viscous forces (μ/L) and consequently it quantifies the relative importance of these two types of forces for given flow conditions. ... The Richardson number is named after Lewis Fry Richardson (1881 - 1953). ... The Rossby number, named for Carl-Gustav Arvid Rossby, is a dimensionless number used in describing fluid flow, usually in geophysical phenomena in the oceans and atmosphere. ... The Schmidt number is a dimensionless number approximating the ratio of momentum diffusivity (viscosity) and mass diffusivity, and is used to characterize fluid flows in where there are simultaneous momentum and mass diffusion convection processes. ... The Sherwood number (Sh) is a dimensionless number used in mass-transfer operation. ... The Stanton number is a dimensionless number which measures the ratio of heat transferred into a fluid to the thermal capacity of fluid. ... The Stokes number is a dimensionless number corresponding to the behavior of particles suspended in a fluid flow. ... In dimensional analysis, the Strouhal number is a dimensionless number describing oscillating flow mechanisms. ... The Weber number is a dimensionless quantity in fluid mechanics that is often useful in analysing fluid flows where there is an interface between two different fluids, especially for multiphase flows with strongly curved surfaces. ... The Weissenberg number is a dimensionless number used in the study of viscoelastic flows. ... A Womersley number is a dimensionless number in biofluid mechanics. ...