Thermophysical specific heat capacity

As described in the previous sections, the changes in the effective thermophysical properties (density, thermal conductivity, and specific heat capacity) are mainly determined by the decomposition process. This process, being kinetic, is not just an univariate function of temperature, but also on time. Therefore, and in contrast to true material properties, effective properties are dependent not only on temperature, but also on time. In order to model the time-dependent physical properties, related kinetic processes must be taken into account, as described by the kinetic equations in Chapter 2. 

Models for the effective thermophysical properties - including mass (density), thermal conductivity, and specific heat capacity - have been developed in Chapter 4. Those material property models are implemented into the heat transfer governing equation in the following. 

A one-dimensional thermal response model was developed to predict the temperature of FRP structural members subjected to fire. Complex boundary conditions can be considered in this model, including prescribed temperature or heat flow, as well as heat convection and/or radiation. The progressive changes of thermophysical properties including decomposition degree, density, thermal conductivity, and specific heat capacity can be obtained in space and time domains using this model. Complex processes such as endothermic decomposition, mass loss, and delatnina-tion effects can be described on the basis of an effective material properties over the whole fire duration. 

Thermophysical Properties of Matter (14 volumes), by Touloukian, Y.S., Kirby, R.K., Taylor, R.E. Lee, T.Y.R. (eds.)(1970-1977). New York, IFI/Plenum Press. Thermal conductivity (vol. 1-3), Specific heat capacity (4-6), Thermal radiative properties, and thermal diffusivity (10), Absolute and Dynamic Viscosity (11), Coefficients of Thermal Expansion (12-13) and index (14). 

W. K. Rhim and K. Osaka, Thermophysical properties measurement of molten silicon by high-temperature electrostatic levitator density, volume expansion, specific heat capacity, emissivity, surface tension and viscosity, J Ciyst Grovrtft 208, 313-321 (2000). 

The selection of the thermal management materials for electronic packaging purposes demands close examination of thermophysical characteristics, such as thermal conductivity and diffusivity, specific heat capacity, coefficient of thermal expansion, and thermal shock resistance. A variety of measurement techniques have been developed to evaluate these properties, but this chapter focuses on thermal conductivity and diffusivity evaluation methods. Each of them is suitable for a limited range of materials, depending on the thermal properties and the medium temperature. The precise determination of the thermal properties of bulk composite materials is challenging. For instance, loss terms for the heat input intended to flow through the sample usually exist and can be difficult to quantify. 

In addition to estimating individual properties, LOADER-2 checks whenever possible that the thermodynamic consistency between properties is maintained. For example, the liquid heat capacity will be compatible with the enthalpy of vaporization and liquid enthalpy. The ideal-gas thermal conductivity will be compatible with the ideal-gas specific heat capacity. By fitting well-behaved representative equations to each property, the program produces a self-contained set of thermophysical property data, which can be used with the main PPDS system. 

The general term thermal properties includes a wide range of properties and phenomena. In the most general sense, transitional phenomena such as glass-transition temperature and melting point or heat transfer theory and applications might be included. In this article, however, the discussions are confined to four polymer properties thermal conductivity, thermal diffusivity, specific heat capacity, and linear thermal expansivity. These properties are sometimes referred to as thermophysical properties. 

W. M. Haynes and R. D. Goodwin, Thermophysical Properties of Normal Butane from 135 to 700 K at Pressures to 70 MPa, U.S. Dept, of Commerce, National Bureau of Standards Monograph 169, 1982, 192 pp. Tabulated data include densities, compressibility factors, internal energies, enthalpies, entropies, heat capacities, fugacities and more. Equations are given for calculating vapor pressures, liquid and vapor densities, ideal gas properties, second virial coefficients, heats of vaporization, liquid specific heats, enthalpies and entropies. 

Generally, the occurrence of a specific mode is determined by droplet impact properties (size, velocity, temperature), surface properties (temperature, roughness, wetting), and their thermophysical properties (thermal conductivity, thermal capacity, density, surface tension, droplet viscosity). It appeared that the surface temperature and the impact Weber number are the most critical factors governing both the droplet breakup behavior and ensuing heat transfer. I335 412 415]... 

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