“…[2, section 7], [3, chapter 4.4] tested this FE–FV method in the case of high‐speed compressible Navier–Stokes flows in complex geometries and obtained very satisfactory results. In , we applied this FE–FV method to problem (1.1)–(1.3), using the implicit Euler method as time discretization. Under the assumptions (homogeneous Dirichlet boundary conditions), m = 0 (no reaction term), (Laplace operator with diffusion coefficient ), with (constant convective velocity), we derived a bound for the ‐ and the ‐error arising with this method.…”