Mixture theory

About: Mixture theory is a research topic. Over the lifetime, 616 publications have been published within this topic receiving 19350 citations.

A mixture model for magneto-rheological materials

Abstract: To model the response of magnetorheological (MR) materials, a continuum theory for a mixture consisting of a fluid continuum and a solid one is developed. In this mixture theory, the structure composed of the magnetizable particles in MR fluids is treated as a solid continuum. The aim of this paper is two-fold. Firstly, we adopt the extended irreversible thermodynamics (EIT) approach as the thermodynamic framework to formulate the general dynamic equations of MR mixtures. Introducing the concept of plastic deformation of the solid continuum, the mechanisms of dissipation are discussed and the evolution equations for the fluxes are derived. Secondly, by virtue of this derivation we study the propagation of an acoustic wave through the MR fluids. This study shows that there exist two longitudinal acoustic waves propagating along the direction of an applied magnetic field.

Single-Channel mixture decomposition using bayesian harmonic models

Abstract: We consider the source separation problem for single-channel music signals. After a brief review of existing methods, we focus on decomposing a mixture into components made of harmonic sinusoidal partials. We address this problem in the Bayesian framework by building a probabilistic model of the mixture combining generic priors for harmonicity, spectral envelope, note duration and continuity. Experiments suggest that the derived blind decomposition method leads to better separation results than nonnegative matrix factorization for certain mixtures.

A variational approach to a micro-structured theory of solid-fluid mixtures

Abstract: In this paper, we present a micro-structured model for describing global deformations of heterogeneous mixtures. In particular, for a saturated solid-fluid mixture, we regard the solid volume fraction as a microstructural parameter so as to enlarge the space of admissible deformations with respect to the classical theory of mixtures. According to the variational approach, the governing equations are obtained as the stationarity of a suitable action functional. The micro-structured model is then forced to establish a second-gradient mixture theory, by introducing among the considered state parameters a suitable internal constraint. Finally, we determine under which (integrability) conditions the additional balance laws, typically employed to close the theory of porous media endowed with the volume fraction, can fit the variational framework.

Mathematical modeling of fluid-solid mixtures

Abstract: The flows of a mixture of solid particles and a fluid have relevance to several important technological applications. There are primarily two approaches that have been used for modeling such solid-fluid systems. In the first approach, the model is obtained by some kind of averaging of the equations of motion. In the second approach, the basic conservation laws are postulated and the ideas in continuum mechanics are used to arrive at appropriate constitutive relations. In this report we use this approach called mixture theory to derive the governing equations of motion for a steady one-dimensional fully developed pipe flow of a mixture of particles and a fluid. We present a brief historical account of the modeling of stress tensors for particles and the fluid. Finally, we discuss the importance of the boundary conditions. 24 refs.