Volumetric heat capacity



Volumetric heat capacity (VHC) describes the ability of a given volume of a substance to store density of the substance. [1]

Dulong and Dulong-Petit law). In fact, the quantity varies from about 1.2 to 4.5 MJ/m³K. For fluids it is in the range 1.3 to 1.9, and for gases it is a constant 1.0 kJ/m³K.

The volumetric heat capacity is defined as having F°).

Thermal inertia

Thermal inertia is a term commonly used by scientists and engineers modelling thermal conductivity and volumetric heat capacity. For example, this material has a high thermal inertia, or thermal inertia plays an important role in this system, which means that dynamic effects are prevalent in a model, so that a steady-state calculation will yield inaccurate results.

The term is a scientific analogy, and is not directly related to the mass-and-velocity term used in mechanics, where inertia is that which limits the acceleration of an object. In a similar way, thermal inertia is a measure of the thermal mass and the velocity of the thermal wave which controls the surface temperature of a material. In equilibrium.

The thermal inertia of a material is defined as a the square root of the product of the material's bulk specific heat capacity:

I=\sqrt{k \rho c}

SI units of thermal inertia are J m − 2 K − 1 s − 1 / 2 or, equivalently, tiu[2].

For planetary surface materials, thermal inertia is the key property controlling the diurnal and seasonal surface temperature variations and is typically dependent on the physical properties of near-surface geologic materials. In remote sensing applications, thermal inertia represents a complex combination of particle size, rock abundance, bedrock outcropping and the degree of induration. A rough approximation to thermal inertia is sometimes obtained from the amplitude of the diurnal temperature curve (i.e., maximum minus minimum surface temperature). The temperature of a material with low thermal inertia changes significantly during the day, while the temperature of a material with high thermal inertia does not change as drastically. Deriving and understanding the thermal inertia of the surface can help to recognize small-scale features of that surface. In conjunction with other data, thermal inertia can help to characterize surface materials and the geologic processes responsible for forming these materials.

Constant volume and constant pressure.

For gases it is useful to distinguish between volumetric heat capacity at constant volume and at constant specific heat capacity.

References

  1. ^ U.S. Army Corps of Engineers Technical Manual: Arctic and Subarctic Construction: Calculation Methods for Determination of Depths of Freeze and Thaw in Soils, TM 5-852-6/AFR 88-19, Volume 6, 1988, Equation 2-1
  2. ^ Thermal inertia and surface heterogeneity on Mars, N. E. Putzig, University of Colorado Ph. D. dissertation, 2006, 195 pp.

See also
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Volumetric_heat_capacity". A list of authors is available in Wikipedia.