The applications of fluid mechanics are so vital that when we observe our surroundings we will find a huge number of applications.
An important application is used in the design of marine vehicles like ships and submarines.
For example, the design of ships involves the principles of buoyancy, Archimedes principle. Even the calculation of meta-center and center of buoyancy enables us to know if a body is submerged or is floating.
One of the common usages of the concepts of fluid dynamics involves the design of important mechanical devices such as centrifugal pumps, turbines, and other hydraulic machinery.
Another important application of fluid mechanics is the design of aircraft which involves the calculation of forces like lift forces, drag forces, weight and thrust force to design the air foil.
It also involves the usage of pressure measurement devices, venturi-meter, orifice meter, pitot tube any many more. Fluid flow is analogous to the heat transfer and can be even applied to other thermal applications as well.
Fluid flows like winds, rivers, ocean currents, etc. can be easily understood.
The applications of fluid mechanics can even be seen in our bodies as well, that is the blood flow in veins of our bodies. Based on the principles of fluid mechanics we can understand reservoir engineering, particle dynamics, etc.