Fluid mechanics is very important subject in core engineering branches and known to be a bit difficult one. But don’t be worried we will make it simple for you with basics of fluid mechanics.
What do you mean by Mechanics?
Mechanics is the sub-category of physical science that deals with immobilized and moving bodies under the impact of a force.
What is fluid?
Fluid is a substance that has propensity to flow. It can be a liquid or gas.
Basic Definition of fluid Mechanics
Basically, Fluid mechanics is defined as science where we study fluid at rest or in motion.
When we study fluid at rest it comes under Fluid statics, on the other side, when we study fluid behaviour under the action of force that results it into motion known as Fluid dynamics.
Solid and fluid mechanics
Fluid differs from solid in such a way that when a force is applied on a solid surface, solids may get deform to a definite extent and post removal of applied force it regains its original shape or it may not.
On the other hand, Generally, fluid possess continuous deformation. When a force is applied on a fluid element it deforms continuously and after removal of force it never regains its original shape except viscoelastic fluid which has tendency to return to its original shape partially or fully after the release of applied force.
Differences between Solid and fluid mechanics
I have stated a few crisp differences between Solid and fluid for better visualization of fluid behaviour.
| Solid | Fluid |
| Under shear stress solid resist in static equilibrium | Under shear stress fluid resists in dynamic equilibrium |
| It may deform or may not | It undergoes continuous deformation that leads to flow |
| Stress is directly proportional to the strain | Stress is directly proportional to the rate of shear strain |
Importance of Fluid mechanics
- Describes physical laws that govern fluid flow
- Recognize cause and effect of fluid flow
- Develops a sense to understand physical mechanism in real world
- Exposes a student to laws of conservation of momentum, mass and energy
- Paves a way to understand fundamentals of engineering applications
Basics of fluid mechanics-FAQs
Fluid mechanics explained the laws that hold true to fluid motion and helps us to understand cause and effect by some characteristic parameters such as pressure and velocity field along with different properties of fluid viscosity, density in different situations like fluid at rest ( fluid static) or motion (fluid dynamics).
Fluid is a substance that has tendency to flow under the effect of stress. It deforms continuously and oppose the stress in dynamic equilibrium manner.