The Grashof number is a dimensionless number in fluid dynamics which approximates the ratio of the buoyancy |viscous]] force acting on a fluid. It is named after the Iranian engineer Franz Grashof. In dimensional analysis, a dimensionless number (or more precisely, a number with the dimensions of 1) is a pure number without any physical units. ... Fluid dynamics is the sub-discipline of fluid mechanics dealing with fluids (liquids and gases) in motion. ... In physics, buoyancy is the upward force on an object produced by the surrounding fluid (i. ... Franz Grashof (July 11, 1826 in Düsseldorf - October 26, 1893 in Karlsruhe) was a German engineer. ...
The product of the Grashof number and the Prandtl number gives the Rayleigh number, a dimensionless number that characterizes convection problems in heat transfer. g (also gee, g-force or g-load) is a non-SI unit of acceleration defined as exactly 9. ... During heat transfer, the energy that is stored in the intermolecular bonds between atoms changes. ... Viscosity is a measure of the resistance of a fluid to deformation under shear stress. ... The Prandtl Number is a dimensionless number approximating the ratio of momentum diffusivity and thermal diffusivity. ... In fluid mechanics, the Rayleigh number for a fluid is a dimensionless number associated with the heat transfer within the fluid. ...
There is an analogous form of the Grashof number used in cases of natural convection mass transfer problems. Mass transfer is the phrase commonly used in engineering for physical processes that involve molecular and convective transport of atoms and molecules within physical systems. ...
g (also gee, g-force or g-load) is a non-SI unit of acceleration defined as exactly 9. ... A fluid is defined as a substance that continually deforms (flows) under an applied shear stress regardless of the magnitude of the applied stress. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: Ï (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is...
References
Jaluria, Yogesh. Natural Convection Heat and Mass Transfer (New York: Pergamon Press, 1980).
When the Grashofnumber N.sub.Gr generally exceeds the critical value determined by the geometrical size of the melting liquid 1 and thermal environmental conditions, a thermal convection 8 occurs in the melting liquid 8.
in the equation of the above-described Grashofnumber increases.
Thus, the Grashofnumber abruptly decreases, and the Grashofnumber can be reduced to be smaller than the critical value due to a certain intensity of the magnetic field.
In fluid mechanics, the Rayleigh number for a fluid is a dimensionless number associated with the heat transfer within the fluid.
The Rayleigh number is defined as the product of the Grashofnumber, which describes the relationship between buoyancy and inertia within a fluid, and the Prandtl number, which describes the relationship between the viscosity of a fluid and its temperature.
In geophysics the Rayleigh number is of fundamental importance: it indicates the presence and strength of convection within a fluid body such as the Earth's mantle, which is a solid but which behaves as a fluid over geological time scales.
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