What are Computational Fluid Dynamics?

Computational Fluid Dynamics (CFD) is the study of the behavior of fluids, liquid and gaseous, by the use of powerful computers running numerical methods software. Knowledge of the interaction of solids with surrounding flowing fluids is of key interest in the design of many mechanical devices. CFD has expanded the topics to which fluid dynamic studies and experiments may be applied.

Traditionally, computational fluid dynamics studies were conducted in wind tunnels or flowing water tanks with real or model planes, cars, and boats. With the use of CFD, the mechanisms of such diverse events as volcanic eruptions, hurricanes, standing vortexes in water or in the air, ocean currents, the course of wildfires and more are potential targets. A limit to these studies is knowledge of the variables that must be defined for each system. Minimum variables include temperature, pressure, and compositions for systems undergoing chemical reactions at a defined boundary.

CFD software is based on the solution of the Navier-Stokes equations, or simplifications of them. The variables of interest are defined for one known boundary in the system. A virtual grid of either two or three dimensions is placed over the system, and the equations are solved for the properties of the incoming and outgoing fluid at each virtual boundary. The development of CFD software paralleled the availability of computational power, as the algorithms require repeated calculation and optimization until solutions are found.

Vehicle design is a frequent goal of fluid dynamics experiments. Air flows around cars effect performance, fuel consumption and noise level. Airplanes, boats, and especially space vehicles rely on these studies for predicting heat or ice buildup as well as streamlining to reduce frictional losses.

Heat dissipation is a major topic in computational fluid dynamics. All electronic components are susceptible to heat buildup and are often enclosed in small boxes with limited airflow. By the use of CFD models, designers can reroute components to better airflow and cooling.

The study of boundary layer conditions are tackled by computational fluid dynamics. The boundary layer refers to the very thin layer of fluid that is static along the surface of a solid that is in the path of a moving fluid. In this microenvironment is where corrosion, heat transfer, and component concentration levels are most critical.

The acquisition of skills to work in the field of computational fluid dynamics usually requires education in chemical engineering or similar pursuits. A thorough understanding of mass transfer, heat transfer, kinetics and fluid dynamics is necessary. The use of commercial CFD application packages is often taught by the software company or the skills are developed on the job.