Galilei number

In fluid dynamics, the Galilei number (Ga), sometimes also referred to as Galileo number (see discussion), is a dimensionless number named after Italian scientist Galileo Galilei (1564-1642).

It may be regarded as proportional to gravity forces divided by viscous forces. The Galilei number is used in viscous flow and thermal expansion calculations, for example to describe fluid film flow over walls. These flows apply to condensers or chemical columns.

${\displaystyle \mathrm {Ga} ={\frac {g\,L^{3}}{\nu ^{2}}}}$

• g: gravitational acceleration, (SI units: m/s²)
• L: characteristic length, (SI units: m)
• ν: characteristic kinematic viscosity, (SI units: m²/s)

See also

• Archimedes number

References

• VDI-Wärmeatlas; 5., extended Edition; VDI Verlag Düsseldorf; 1988; page Bc 1 (German)
• W. Wagner; Wärmeübertragung; 5., revised Edition; Vogel Fachbuch; 1998; page 119 (German)
• Akita, K.; Yoshida, F. Bubble Size, Interfacial Area, and Liquid-Phase Mass Transfer Coefficient in Bubble Columns. Industrial & Engineering Chemistry Process Design and Development 1974, 13 (1), 84–91. https://doi.org/10.1021/i260049a016.
• Keshavarz Moraveji, M.; Ebrahimi Fakhari, M.; Mohsenzadeh, E.; Davarnejad, R. Hydrodynamics and Oxygen Mass Transfer in a Packed Bed Split-Cylinder Airlift Reactor Containing Dilute Alcoholic Solutions. Heat and Mass Transfer 2012, 49 (1), 11–19. https://doi.org/10.1007/s00231-012-1056-0.

External links

• Website referring to the Galileo number with calculator
• Table of dimensionless numbers (German)^{[permanent dead link]}
• Table of dimensionless numbers (German)^{[permanent dead link]}