# Diploma Fluid Mechanics and Fluid Power Study Materials – Unit 1

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We have added Diploma Fluid Mechanics and Fluid Power study material for N scheme syllabus. You can download Diploma Fluid Mechanics and fluid power study material as pdf

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Fluid Mechanics and Fluid Power

Unit – 1

Fluid – definition-classification. Properties – density, specific gravity, specific weight, specific volume, dynamic viscosity, kinematic viscosity, surface tension, capillarity, vapour pressure and compressibility

Unit 1 – Three marks

1. Define Fluid

Fluid is a substance which is capable of flowing. Fluid may be liquid or gas.

1. What are the classifications of fluids?

Fluids are classified into five types

1. Ideal fluid
2. Real fluid
3. Newtonian fluid
4. Non – Newtonian fluid
5. Ideal Plastic fluid
6. What is Real fluid?

A real fluid which possess viscosity, In actual practice all fluids are real fluids

1. Define Newtonian Fluid

A Newtonian fluid is defined as the fluid in which the shear stress is directly proportional to the rate of shear strain (velocity gradient)

1. Define Non – Newtonian fluid.

Non – Newtonian fluid is defined as the a real fluid in which the shear stress is not proportional to the rate of shear strain (or velocity gradient)

1. What is Ideal Plastic fluid?

A fluid in which the shear stress is more than the yield value and shear stress is proportional to the rate of shear strain (or velocity gradient) is known as ideal plastic fluid.

1. Mention the properties of fluid
• Density
• Specific Weight
• Specific volume
• Specific gravity
• Viscosity
• Compressibility
• Surface tension
• Capillarity
• Vapour pressure
• Cavitation
1. What is Density?

Density or mass density of a fluid is defined as the ratio of the mass of the fluid to its volume

Mass per unit volume of a fluid is called ensity

Density = Mass of fluid / Volume of fluid

1. Define specific weight

Specific weight or weight density of a fluid is the ratio between weight of a fluid to its volume

Specific weight = Weight of fluid / volume of fluid

1. What is viscosity?

Viscosity id defined as the property of a fluid which offers resistance to the movement of the flowing fluid

11 .  Define Newtons Law of Viscosity

Newtons law of viscosity is defined as the shear stress of fluid is directly proportional to the rate of shear strain.

1. What is Compressibility?

Compressibility is defined as the reciprocal of the bulk modulus of elasticity, which is defined as compressive stress to volumetric strain

Bulk modulus = Compressive stress / Volumetric strain

Compressibility = 1 / K

Compressibility = Volumetric Strain / Compressive stress

1. Explain Surface tension of a liquid

Surface tension is the attractive force in liquids that pulls surface molecules into the rest of the liquid, minimizing the surface area. These attractive forces are due to electrostatic forces

1. What is capillarity?

Capillarity is defined as a phenomenon of rise or fall of a liquid surface in a small tube, when the tube is immersed in the liquid

1. What is cavitation?

Cavitation is the phenomenon of formation of vapour bubbles of a flowing liquid in a region where the pressure of the liquid falls below the vapour pressure and sudden collapsing of these vapour bubbles in a region of higher pressure

1. Define Vapour pressure of a liquid.

Vapour pressure is a measure of the tendency of a material to change into the gaseous or vapour state, and it increases with temperature. The temperature at which the vapour pressure at the surface of a liquid becomes equal to the pressure exerted by the surroundings is called the boiling point of the liquid. 