Abstract
This article describes a systematic approach in building a flow solver for large eddy simulation (LES). Finite volume discretizations of the filtered, incompressible, Navier-Stokes equations were explained. The theory progresses to the description of the step-by-step process (mainly in increasing functionality or capability) in developing a three-dimensional, unstructured Cartesian mesh, parallel code after evaluating numerical factors, and available options carried out earlier. This was followed by a presentation of results produced from the simulations of laminar flow, related to the validation of the source codes, which indicates that the flow solver is behaving satisfactorily.