Fluid mechanics is the branch of physics that studied the mechanics of fluids (liquids, gases, and plasmas) and the forces on them. Fluid mechanics can be divided into fluid:
Fluid Statics:
The study of fluids at rest. Fluid statics or hydrostatics is the branch of fluid mechanics that studies fluids at rest. It is the study of the conditions under which fluids are at rest in stable equilibrium and is comparison with fluid dynamics, the study of fluids in motion. Hydrostatics is the fundamental of hydraulics, the engineering of equipment for storing, transporting and using fluids. It is also relevant to geophysics and astrophysics for example, in understanding plate tectonics and the anomalies of the Earth's gravitational field, to meteorology, to medicine in the context of blood pressure, and many other fields.
Hydrostatics offers physical explanations for many phenomena of routine life, such as atmospheric pressure changes with altitude, wood and oil float on water, and the surface of water is always flat and horizontal whatever the shape of its container.
Fluid Dynamics:
The study of the effect of forces on fluid motion. Fluid dynamics is a part of fluid mechanics that deals with fluid flow. The natural science of fluids (liquids and gases) in motion. It has several parts including aerodynamics; the study of air and other gases in motion and hydrodynamics; the study of liquids in motion. 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, understanding nebulae in interstellar space and modelling fission weapon detonation. Some of its principles are used in traffic engineering, where traffic is treated as a continuous fluid, and crowd dynamics.
The solution of a fluid dynamics problem typically involves calculations of various properties of the fluid, such as velocity, pressure, density, and temperature, as functions of space and time.
Fluid mechanics, especially fluid dynamics, is an active field of research with many problems that are partly or whole unsolved. Fluid mechanics are mathematically complex, and can best be solved by numerical methods, typically using computers. A modern discipline, called computational fluid dynamics (CFD), is devoted to this approach to solve fluid mechanics problems. Particle image velocimetry, an experimental method for visualizing and analyzing fluid flow, also takes advantage of the highly visual nature of fluid flow.