This paper is concerned with the homogenization of a diffusion-reaction process in a domain undergoing an evolution of the microstructure. The main novelty is the consideration of a chemical process on a hypersurface, where the surface itself is evolving. After transformation to a description in a fixed domain, we employ methods of periodic homogenization to arrive at a limit problem in the bulk coupled with problems in a reference cell. Here, the structural evolution takes place only in the reference structure. Additional problems come from nonlinear reaction rates, which require the Kolmogoroff compactness criterion for the derivation of suitable a priori estimates. The results can be used as a modeling tool and for the investigation of complex biological and chemical systems in porous media, for example, carbon sequestration or biological enhanced oil recovery.
559Details of the derivation can be found in [8]. The main physical assumption contained in the nondimensionalization procedure is the fact that the diffusivity on the boundary is orders of magnitude smaller than in the bulk. Of course, other scalings are possible as well. With the same method, one could, for example, consider the diffusion of a second substance in the bulk whose diffusivity D 0 satisfies D 0 D " 2 . A systematic investigation of the dependence of homogenization limits in reaction-diffusion scenarios on different scaling factors can be found in the study of Peter [9]. However, this only applies to processes in various bulk phases. To the knowledge of the author, no methods are known to treat systems similar to (3) and (4), where the ratio D D is not of order " 2 . Concerning the curvature, the assumption given earlier implies that the characteristic curvature is constant during the evolution of the surface. This restricts changes of the underlying geometry. For example, a process that transforms a spherical shape to a finely fingered structure might not fulfill these assumptions.
Related worksSeveral works apply homogenization methods and coordinate transformations to treat problems in evolving domains: Peter [4,10] considers models for chemical degradation of concrete structures, where the domain consists of a porous matrix, an air, and a water phase. Because of a carbonation reaction, water is produced and thus leads to the growth of the latter phase. A summary of the mathematical method can also be found in [11]. Meier [5] considers a similar situation but focuses on mathematical properties of the two-scale limit system. In the latter references, one can also find information on how to incorporate a reaction driven change of the 561 1. One transforms the equations formally by using appropriate transformation rules for functions and differential operators. This is used in most works on problems in noncylindrical domains, for instance in the references cited above. 2. One defines a weak formulation of the problem in natural coordinates and uses integral transformations to obtain a weak formulation in referential coordinates. This rigor...