Thermophysical properties of high porosity metal foams

Theoretical prediction of effective properties for multiphase material systems is very important not only to analysis and optimization of material performance, but also to new material designs. This review first examines the issues, difficulties and challenges in prediction of material behaviors by summarizing and critiquing the existing major analytical approaches dealing with material property modeling. The focus then shifts to some recent advances in numerical methodology that are able to predict more accurately and efficiently the effective physical properties of multiphase materials with complex internal microstructures. A random generation-growth algorithm is highlighted for reproducing multiphase microstructures, statistically equivalent to the actual systems, based on the geometrical and morphological information obtained from measurements and experimental estimations. Then a high-efficiency lattice Boltzmann solver for the corresponding governing equations is described which, while assuring energy conservation and the appropriate continuities at numerous interfaces in a complex system, has demonstrated its numerical power in yielding accurate solutions. Various applications are provided to validate the feasibility, effectiveness and robustness of this new methodology by comparing the predictions with existing experimental data from different transport processes, accounting for the effects due to component size, material anisotropy, internal morphology and multiphase interactions. The examples given also suggest even wider potential applicability of this methodology to other problems as long as they are governed by the similar partial differential equation(s). Thus, for given system composition and structure, this numerical methodology is in essence a model built on sound physics principles with prior validity, without resorting to ad hoc empirical treatment. Therefore, it is useful for design and optimization of new materials, beyond just predicting and analyzing the existing ones.

Predictions of effective physical properties of complex multiphase materials

Estimating correlations for the effective thermal conductivity of granular materials

On the effective thermal conductivity of aluminum metal foams: Review and improvement of the available empirical and analytical models

Effect of lumen size on the effective transverse thermal conductivity of unidirectional natural fiber composites

The authors propose a method of calculating the effective thermal conductivity of multicomponent mixtures as a function of their structure, the thermal conductivities of the components, their concentrations, and other parameters.

Thermal conductivity of multicomponent mixtures

The process of heat transfer in fibrous materials with a random structure is examined and a method is proposed for calculating the effective thermal conductivity as a function of the characteristic parameters of the system (thermal conductivities of the components, their volume concentration, temperature, pressure of the interstitial gas, etc.).

Thermal conductivity of fibrous systems

We propose a new stable model of a granular or sintered material in a form with a secondorder structure, with mutually penetrating components. We derive the functional relationships for the calculation of the coefficients of generalized conductivity for the granular and sintered materials.

The thermal conductivity of granular and weakly sintered materials

The main methods of analysis of heat transfer in mixtures of nonreacting gases are discussed. A new model and method of calculating the thermal conductivity is proposed.

Thermal conductivity of binary gas mixtures

A model of the structure of a Bazhenov suite and a method for calculating its effective thermal conductivity are proposed.

G. N. Dul'nev

Papers

Thermal conductivity of multicomponent mixtures

Thermal conductivity of fibrous systems

The thermal conductivity of granular and weakly sintered materials

Thermal conductivity of binary gas mixtures

Model of the structure of and the effective thermal conductivity of a bazhenov suite