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A number of materials contract on heating within certain temperature ranges; this is usually called negative thermal expansion, rather than "thermal contraction".For example, the coefficient of thermal expansion of water drops to zero as it is cooled to 3.983 °C (39.169 °F) and then becomes negative below this temperature; this means that water has a maximum density at this temperature, and ...
In fluid dynamics, the Graetz number (Gz) is a dimensionless number that characterizes laminar flow in a conduit. The number is defined as: [1] = where D H is the diameter in round tubes or hydraulic diameter in arbitrary cross-section ducts
This concept lies in the basis for the kinetic theory of matter and thermal expansion of matter, which states as the temperature of a substance rises, so does the average kinetic energy of its molecules. As such, a rise in kinetic energy requires more space between the particles of a given substance, which leads to its physical expansion. [2]
To distinguish these two thermal expansion equations of state, the latter one is called pressure-dependent thermal expansion equation of state. To deveop the pressure-dependent thermal expansion equation of state, in an compression process at room temperature from (V 0, T 0, P 0) to (V 1, T 0,P 1), a general form of volume is expressed as
β is the coefficient of volume expansion (equal to approximately 1/T for ideal gases) T s is the surface temperature; T ∞ is the bulk temperature; L is the vertical length; D is the diameter; ν is the kinematic viscosity. The L and D subscripts indicate the length scale basis for the Grashof number.
β is the thermal expansion coefficient (equals to 1/T, for ideal gases, where T is absolute temperature). is the kinematic viscosity; α is the thermal diffusivity; T s is the surface temperature; T ∞ is the quiescent temperature (fluid temperature far from the surface of the object) Gr x is the Grashof number for characteristic length x
Induction heating is a non contact heating process which uses the principle of electromagnetism induction to produce heat in a work-piece. In this case thermal expansion is used in a mechanical application to fit parts over one another, e.g. a bushing can be fitted over a shaft by making its inner diameter slightly smaller than the diameter of the shaft, then heating it until it fits over the ...
is pressure, temperature, volume, entropy, coefficient of thermal expansion, compressibility, heat capacity at constant volume, heat capacity at constant pressure. Maxwell's relations are a set of equations in thermodynamics which are derivable from the symmetry of second derivatives and from the definitions of the thermodynamic potentials .