is the sub-discipline of fluid mechanics dealing with fluids (liquids and gases) in motion and has several sub-disciplines itself, including aerodynamics (the study of gases) and hydrodynamics (the study of liquids). Fluid dynamics has a wide range of applications, including calculating forces and moments on aircraft, determining the mass flow rate of petroleum through pipelines, predicting weather patterns and reportedly modeling fission weapon detonation.

Fluid dynamics offers a mathematical structure that underlies these practical disciplines and that embraces empirical and semi-empirical laws, derived from flow measurement, used to solve practical problems. The solution of a fluid dynamics problem typically involves calculation of various properties of the fluid, such as velocity, pressure, density, and temperature, as functions of space and time.