What is fluid mechanics?
Before understanding fluid mechanics let us first understand ‘mechanics’.
Mechanics is a physical science which deals with the bodies which are either moving or stationary, under the influence of some external force.
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Mechanics can be further divided into two parts

Statics

Dynamics
Statics deals with the bodies which are at rest.
Dynamics deals with the bodies which are in motion.
Fluid mechanics is a sub category of mechanics.
Fluid mechanics deals with the behavior of fluids which are either stationary or in motion. It also deals with the interaction of fluids with the boundaries.
Fluid mechanics is sometimes also known as fluid dynamics. Fluids statistics is taken as a special case (of fluid dynamics) where velocity of flow is zero.
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Fluid dynamics can further be divided into several categories
Hydrodynamics
It is the study of fluid motion when the fluid flow is approximated as incompressible.
Hydraulics
It is a sub category of hydrodynamics which deals with the flow of liquid through pipes and channels.
Gas dynamics
It is the study of fluid motion when the density of fluid varies.
Aerodynamics
It deals with flow of fluids over aircraft, rockets or automobiles at high or low speeds.
There are also some other categories of fluid dynamics like hydrology, oceanography and meteorology which deals with naturally occurring flow.
Applications of fluid mechanics
Below are some application areas of fluid mechanics (or fluid dynamics)
 Geophysical phenomenon
 Navel architecture
 Hydrology
 Aerospace
 Aerodynamics
 Microfluidics
 Quantum mechanics
 Magnetohydrodynamic
 Cardiovascular study
 Biophysics
 Pipe network
 Turbomachinery
Also read:
Definition and types of fluids
What are different types of fluid flows?
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