Fluid mechanics, science concerned with the response of fluids to forces exerted upon them. It is a branch of classical physics with applications of great.Fluid mechanics is the study of fluid behavior (liquids, gases, blood, and plasmas) at rest and in motion. Fluid mechanics has a wide range of applications in mechanical and chemical engineering, in biological systems, and in astrophysics.Fluid mechanics, the branch of science that deals with the study of fluids (liquids and gases) in a state of rest or motion is an important subject of Civil, Mechanical and Chemical Engineering. Its various branches are fluid statics, fluid kinematics and fluid dynamics. It helps us understand the behavior of fluid under various forces and at different atmospheric conditions, and to select the proper fluid for various applications. This field is studied in detail within Civil Engineering and also to great extent in Mechanical Engineering and Chemical Engineering. It is difficult indeed. The primary reason is there seems to be more exceptions than rules. This subject evolves from observing behaviour of fluids and trying to put them in the context of mathematical formulation. Many phenomena are still not accurately explained.
The basic fluid mechanics principles are the continuity equation (i.e. conservation of mass), the momentum principle (or conservation of momentum) and the energy equation. Fluid mechanics helps us understand the behavior of fluid under various forces and at different atmospheric conditions, and to select the proper fluid for various applications. This field is studied in detail within Civil Engineering and also to great extent in Mechanical Engineering and Chemical Engineering.