Thermal Diffusivity


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thermal diffusivity

[′thər·məl ‚di·fyü′siv·əd·ē]
(physics)

Thermal Diffusivity

 

a physical parameter of a substance that characterizes the rate of change of its temperature in transient thermal processes. Thermal diffusivity is a measure of the thermal-inertia properties of a substance. It is numerically equal to the ratio of the substance’s thermal conductivity and the product of its specific heat (at constant pressure) and density. Thermal diffusivity is expressed in m2/sec.

thermal diffusivity

The thermal conductivity divided by the product of the specific heat and unit weight; an index of the ease with which a material undergoes a change in temperature.
References in periodicals archive ?
Such large temperature changes cause significant change in sheet material properties like density, specific heat, thermal conductivity, and thermal diffusivity.
As can be seen from Figures 10 and 11, this effect decreases when the ratio between the thermal diffusivity of the grout and that of the ground increases; this ratio is 0.
In this work, a fully automatic and fully contactless method of heat capacity, thermal diffusivity and thermal conductivity determination based on one measurement is presented.
A new handheld instrument that can measure thermal conductivity and thermal diffusivity of any medium in only two minutes is now available in the UK from LABCELL Ltd.
For that purpose, an innovative laboratory device will be developed and pilot-tested allowing for dry and saturated rocks measurements of thermal conductivity and thermal diffusivity at pressures and temperatures that are simultaneously raised to values up to 200 MPa and 200C, respectively.
In the mass-heat transport analogy, the diffusion coefficient (D*) is modeled as an effective thermal diffusivity given by
Thermal diffusivity of the samples was measured on Netzsch system (Model, LFA427, Netzsh Corp.
The material has thermal diffusivity properties comparable to other refractory materials, but its low density provides bulk heat capacity and thermal conductivity values that are much lower than typical foundry aggregates.
Labcell Ltd have introduced a new thermal conductivity measurement system which uses the single needle heat pulse technique to calculate thermal conductivity, and which is capable of concurrently determining thermal conductivity with thermal diffusivity.