Unified streamline, heatline and massline methods for the visualization of two-dimensional heat and mass transfer in anisotropic media

Many of the actual materials are anisotropic, ranging from natural products to the most sophisticated composite materials. Special emphasis needs to be devoted to the heat and mass transfer calculations in anisotropic media, and to the development of visualization tools for the transport phenomena occurring in such media, similarly to what happens with isotropic media. The most adequate tools for visualization purposes are the streamlines, the heatlines and the masslines, when dealing with two-dimensional steady problems without source terms. Moreover, further attention needs to be devoted to the diffusion coefficients for the streamfunction, heatfunction and massfunction, whose contour plots are used for visualization purposes. This is specially important for domains of marked anisotropy or for domains involving media of different properties, or even conjugate diffusion/convection heat and mass transfer problems. Once defined the proper diffusion coefficients, it is proposed a unified physical treatment, as well as a unified treatment to evaluate the function's fields by using the same numerical procedures and code routines as for the primitive conserved variables. The unified approach is illustrated through pure conduction heat transfer problems, natural convection heat transfer in a porous enclosure, and conjugate conduction-convection heat transfer. (C) 2002 Elsevier Science Ltd. All rights reserved.