Finite volume solution of integer order anomalous diffusion
摘要
This paper presents consistent finite-volume schemes for the two-dimensional Bevilacqua–Galeão–Costa (BGC) anomalous diffusion equation on a uniform structured grid. Custom compact stencils are used to discretise the biharmonic operator in both interior and boundary control volumes, ensuring conservative spatial operators. A von Neumann stability analysis compares fully implicit and explicit time integrations, while verification via the method of manufactured solutions confirms second-order spatial and first-order temporal accuracy. Transient simulations across a range of retention factors demonstrate how the fourth-order term influences anomalous diffusion behaviour.