# Fluid Dynamics Questions

Fluid dynamics is a sub-discipline of fluid mechanics concerned with the fluid’s motion. Fluid dynamics is the branch of science that deals with the movement of gases and liquids. Fluid dynamics is used in the study of plate tectonics, ocean tides, weather patterns, the evolution of planets, and blood circulation.

Hydrodynamics and aerodynamics are the sub-disciplines of fluid dynamics. The study of the pattern of airflow around aeroplanes and automobiles to increase the efficiency of motion is known as aerodynamics. The flow of underground water, water through pipes, and around ships is studied in hydrodynamics.

Liquid or gas flow patterns are affected by three factors:

• Characteristics of the fluid
• The shape of the solid surface
• Flow speed

Characteristics of the fluid:

• Viscosity
• Compressibility
• Density

Viscosity is the measure of resistance to flow or internal friction. For example, we can make out that honey is denser/viscous than water. This helps us to know why water flows more easily than honey.

Flow patterns incompressible fluids are more complicated to study than incompressible ones. The property that lets fluid be compressed into a smaller volume is compressibility.

Types of fluid flow are:

• Laminar or turbulent flow
• One, two and three-dimensional flow
• Uniform and non-uniform flow
• Compressible or incompressible flow
• Rotational or irrotational flow

## Important Fluid Dynamics Questions with Answers

1. Define fluid.

Fluid is a liquid, gas, or other material that flows and undergoes deformation continuously when an external force or shear stress is applied.

2. Can the fluid withstand shear force?

Fluids cannot withstand shear force and have zero shear modulus. It undergoes deformation when a shear force is applied.

3. Which among the following use water as the fluid?

1. Vehicles
2. Television
3. Refrigerator
4. Micro oven

Explanation: In the refrigerator, fluids aid in transferring heat from the high-temperature area to the low-temperature area.

4. Disorderly mode of flow in liquids is referred to as _____.

1. Flowy
2. Breezy
3. Turbulent
4. Windy

Explanation: The irregular and disorderly flow of fluids are known as turbulent flow.

5. The layer of fluid that sticks to a solid surface is called ______.

1. Boundary layer
2. Fluid layer
3. Liquid layer
4. Solid layer

Explanation: This boundary layer is responsible for the decrease in the flow speed of the fluid.

6. Water contains which of the following energies?

1. Solar energy and nuclear energy
2. Thermal energy
3. Kinetic energy and potential energy
4. Geothermal energy

Answer: c) Kinetic energy and potential energy.

Explanation: Water contains both kinetic energy and potential energy, and hence it is used in the generation of electricity.

7. Choose YES or NO: Can the forces acting on the aircraft be calculated using fluid dynamics?

1. YES
2. NO

Explanation: The forces acting on the aircraft are calculated using fluid dynamics.

8. In which type of fluid flow do particles move along a well-defined path?

1. Turbulent flow
2. Laminar flow
4. Incompressible flow

Explanation: In laminar flow, particles move along a well-defined path.

9. Define irrotational flow.

It is defined as the type of flow where fluid particles do not rotate about their own axis when they flow along the flow lines.

10: Choose YES or NO: Is a three-dimensional flow seen in liquids.

1. YES
2. NO