Fluid Flow

Fluid flow is generally the motion of a fluid that is subjected to different unbalanced forces. It is mainly a part of fluid mechanics and fluid flow generally deals with the dynamics of the fluid. The motion of the fluid continues till different unbalanced forces are applied to the fluid.

For example, if you are pouring a water bottle by mug then the flow or the velocity of the water is very high over the lip of the mug and very low at the bottom half of the mug. Here the unbalanced force is gravity and the flow of water continues till the mug is tilted and the water is available in the mug.

Types of Fluid

There are different types of fluid available such as real fluid, Newtonian fluid, non-Newtonian fluid, ideal plastic fluid, incompressible fluid, and compressible fluid.

Real fluids mainly possess viscosity. Newtonian fluid obeys the Newton law of viscosity and the non-Newtonian law does not obey the Newton law of viscosity. In the case of ideal plastic fluid the shear stress is proportional to the velocity gradient and also the shear stress is more than the yield value. In the case of an incompressible fluid, the density of the fluid does not change when any external force works on it. The viscosity of an ideal fluid is zero and the density is constant. Incompressible force possesses the Mach number \(M<0.3\) and the compressible fluid possess a Mach number between 0.3 to 1.

Types of Fluid Flow

Fluid flow can be steady, unsteady, viscous, or non-viscous. In the case of steady fluid flow at any point of the path, the velocity of the fluid is constant. But in the case of unsteady fluid flow the velocity of the fluid changes between any two points. The measurement of the thickness of the fluid is known as viscosity and there are many viscous fluids available such as oil, shampoo, etc. In the case of uniform flow the velocity of a flow at any instant time should be the same in terms of both magnitude and direction between any two points but in the case of non-uniform flow velocity changes from point to point at any instant time.

Laminar and Turbulent Flow

In the case of laminar flow or streamline flow mainly fluid flows in parallel layers and there is no disruption between the layers. The case of turbulent flow contains chaotic property changes such as rapid variation of pressure and also flow velocity. In the case, rotational flow the particles of the fluids are rotating with their own axis but in the case of irrotational flow, particles are not rotating about their own axis.

FAQs about Fluid Flow

Q.1 What are the factors that affect fluid flow?

Answer: The factors that affect the fluid flow are the viscosity of the fluid, density, and velocity of the fluid.

Q.2: Give an example of laminar flow in real life.

Answer: Blood circulation throughout our body is an example of laminar flow in real life. The flow of air over an aircraft wing is also an example of laminar flow.