We were discussing the various basic concepts of strength of materials and also the basic concepts of thermal engineering in our previous posts. After looking strength of materials and thermal engineering topics, we will go ahead to start a new subject i.e. Fluid mechanics with the help of this post.

Today we will start here with very basic term of fluid mechanics i.e. meaning and significance of fluid mechanics with the help of this post.

### Fluid Mechanics

Fluid mechanics is basically defined as the branch of science which deals with the behavior, role in engineering life and flow of fluids i.e. Liquids and gases.

We have used a term here i.e. fluid. Let me first provide you a brief introduction for fluid.

Fluids are divided in to liquid and gases. Liquid is hard to compress and it will secure the shape according to the shape of its container with an upper free surface.

While gases are easy to compress and gases will expand to fill its container. Therefore there will not be any upper free surface in case of gases.

So, the basic difference between liquids and gases are nature of compressibility.

## Let us come to the main subject i.e. Basic definition and significance of fluid mechanics

So as we have discussed above, very simple definition of fluid, Fluid mechanics is basically defined as the branch of science which deals with the behavior and flow of fluids i.e. Liquids and gases.

Science of flow has been classified in two types i.e. hydraulics and hydrodynamics. Hydraulics is born from experimental studies and hydrodynamics is developed from theoretical studies.

Hydraulics and hydrodynamics both are merged now and termed as Fluid mechanics. Therefore, we will further study hydraulics and hydrodynamics in the category of fluid mechanics.

In simple, fluid mechanics will have following parts that we will have to study in our upcoming posts.

### Fluid Statics

A part of fluid mechanics where we study fluid at rest will be termed as fluid statics. We will analyze the fluid under static condition i.e. fluid will not be in motion in this case.

### Fluid kinematics

A part of fluid mechanics where we study fluid in motion without considering the effect of pressure forces will be termed as fluid kinematics. We will analyze here the fluid under motion, but we will neglect the effect of pressure forces.

### Fluid Dynamics

A part of fluid mechanics where we study fluid in motion with considering the effect of pressure forces will be termed as fluid dynamics. We will analyze here the fluid under motion and we will also consider the effect of pressure forces too.

So we have discussed here the basic definition of fluid mechanics and we have also seen here three components of fluid mechanics.

Now we will go ahead to discuss the characteristics of a fluid in our next post.

Do you have suggestions? Please write in comment box.

### Reference:

Fluid mechanics by Y. Nakayama and R F Boucher