  The aim of this article is to present a comprehensive methodology for the
verification of computational fluid dynamics (CFD) solvers with a special
attention to aspects pertinent to discretizations with orders of accuracy
(OOAs) higher than two. The method of manufactured solutions (MMS) is adopted
and a series of manufactured solutions (MSs) is introduced that examines
various components of CFD solvers for free flows (not bounded by walls),
including inviscid, laminar and turbulent problems when the latter are modelled
by the Reynolds-averaged Navier-Stokes (RANS) equations. The treatment of
curved elements is also examined. These MSs are furthermore conceived with
demonstrated suitability for the verification of OOAs up to the sixth. Each MS
is as well utilized to discuss salient aspects useful to the code verification
methodology such as the relative qualities of the most useful norms in
measuring the discretization error, the sensitivity analysis of the
verification process to forcing function terms, the relation between residual
minimization and discretization error convergence in iterative solutions and
finally the sensitivity of high-order discretizations to grid stretching and
self-similarity. Furthermore, scripts and code are provided as accompanying
material to assist the interested reader in reproducing the verification
results of each manufactured solution (MS).
