CFD is a branch of fluid mechanics that has application in many fields, such as aerodynamics, weather simulation and environmental engineering. It uses numerical analysis and data structures to analyse and predict outcomes for situations involving fluid flow of either liquid or gas.
The geometry and physical limits of the exercise are usually defined using Building Information Modelling (BIM) or Computer Aided Design (CAD). Boundary conditions are specifically defined. The volume occupied by the fluid is then divided into a mesh of discrete cells; the mesh may be uniform or non-uniform, consisting of a combination of geometric elements, such as hexahedral, tetrahedral or pyramidal. The governing equations for analysis are prescribed, for instance those of heat and momentum transfer, fluid motion or chemical species conservation. Once CFD simulation is underway, the equations are solved iteratively, providing either steady state or transient results.
Because of the large number of calculations involved, CFD requires considerable computing power. Nowadays there are software platforms which are browser based, allowing analysis to be carried out using as many cloud-based servers as may be required by the task.