Mathematical Problems in Engineering
Volume 2008 (2008), Article ID 579172, 30 pages
doi:10.1155/2008/579172
    
    Review Article
    An Anisotropic Constitutive Equation for the Stress Tensor of Blood Based 
                        on Mixture Theory
    
    1National Energy Technology Laboratory (NETL), U.S. Department of Energy, P.O. Box 10940, Pittsburgh, PA 15236, USA
2Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
    
    
    
    Received 20 June 2008; Accepted 18 July 2008
Academic Editor: K. R. Rajagopal
    	
    
       
    Copyright © 2008 Mehrdad Massoudi and James F. Antaki. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
     
    
    
   
 
Abstract
Based on ideas proposed by Massoudi and Rajagopal (M-R), we develop a model for blood 
                  using the theory of interacting continua, that is, the mixture theory. We first provide a brief review
                   of mixture theory, and then discuss certain issues in constitutive modeling of a two-component 
                   mixture. In the present formulation, we ignore the biochemistry of blood and assume that blood is 
                   composed of red blood cells (RBCs) suspended in plasma, where the plasma behaves as a linearly
                    viscous fluid and the RBCs are modeled as an anisotropic nonlinear density-gradient-type fluid. We
                     obtain a constitutive relation for blood, based on the simplified constitutive relations derived for 
                     plasma and RBCs. A simple shear flow is discussed, and an exact solution is obtained for a very
                      special case; for more general cases, it is necessary to solve the nonlinear coupled equations 
                      numerically.