The paper is concerned with development of a new finite-volume method for a class of chemotaxis models and for a closely related
haptotaxis model. In its simplest form, the chemotaxis model is described by a system of nonlinear PDEs: a convection-diffusion
equation for the cell density coupled with a reaction-diffusion equation for the chemoattractant concentration. The first
step in the derivation of the new method is made by adding an equation for the chemoattractant concentration gradient to the
original system. We then show that the convective part of the resulting system is typically of a mixed hyperbolic-elliptic
type and therefore straightforward numerical methods for the studied system may be unstable. The proposed method is based
on the application of the second-order central-upwind scheme, originally developed for hyperbolic systems of conservation
laws in Kurganov et al. (SIAM J Sci Comput 21:707–740, 2001), to the extended system of PDEs. We show that the proposed second-order
scheme is positivity preserving, which is a very important stability property of the method. The scheme is applied to a number
of two-dimensional problems including the most commonly used Keller–Segel chemotaxis model and its modern extensions as well
as to a haptotaxis system modeling tumor invasion into surrounding healthy tissue. Our numerical results demonstrate high
accuracy, stability, and robustness of the proposed scheme.
Mathematics Subject Classification (2000) 76M12 - 92C17 - 35M10