The Fluid Dynamics presents a number of practical engineering cases, which range from simple ventilation systems to the most complex aerodynamic and hydrodynamic projects.

Due to this application diversity, its problems have always been the object of thorough investigation, both through an experimental approach, in which wind and water tunnel tests are conducted, as well as a theoretical approach, where one seeks the solution of the mathematical models that govern the flow.

In the theoretical approach, models are formulated based on the principles of mass, quantity of movement and energy conservation. Nevertheless, in Fluid Dynamics, these principles assume the form of non-linear partial differential equations, for which there is no known general analytic solution. On the contrary, analytical solutions are known for a very narrow collection of problems that comprise a small part of the practical problems and applications.

Such conditions have nourished the development of numerical simulation techniques, as a natural alternative to the analytical methods, to obtain approximate solutions. Such techniques make a line of research known today as Computational Fluid Dynamics (CFD).

Nowadays the numerical methods have become a common tool in engineering offices, allowing the simulation of a number of alternatives to a problem, in a short time frame and with reduced costs, compared to those necessary to perform the correspondent rehearsals.

The correct and efficient use of the CFD depends a great deal of the knowledge the user has of the methods involved. As robust as these programs are, they are not foolproof, and there is no universally accepted method for all applications. So it is up to the engineer to choose the best method fit to the considered application. It is evident the need for a professional with basic knowledge of these methods.

Dynamis has chosen the software PHOENICS to perform the simulations, given its history of development (since the late 1970’s), and the focus on the thermal area given by it creator, professor Brian Spalding.

A case that demonstrates the use of CFD is shown below. A burner injects methane on a air stream, and the combustion occurs producing water and CO₂.

The following picture shows the visualization of the gas flow through the temperature colored vectors.