The Flow of Water in a Whirlpool of the River - Free Vortex

A whirlpool is a swirling body of water that forms when opposing currents meet and create a circular motion. The flow of water in a whirlpool can be categorized as a free vortex. Let's understand why:

1. Definition of a Free Vortex:
A free vortex is a flow pattern in which fluid particles rotate around a central axis without any external force or torque acting on them. In this type of vortex, the velocity of the fluid decreases as the radius increases, maintaining angular momentum.

2. Characteristics of a Free Vortex:
- Fluid particles move in concentric circles around a central point or axis.
- The velocity of the fluid decreases as the distance from the center increases.
- The pressure in the vortex is lowest at the center and increases towards the outer edges.
- The angular velocity remains constant at each radius.

3. Flow of Water in a Whirlpool:
When opposing currents meet in a river or any body of water, a whirlpool can form. The flow of water in a whirlpool exhibits the characteristics of a free vortex:
- The water particles rotate in a circular motion around a central point.
- The velocity of the water decreases as it moves away from the center of the whirlpool.
- The pressure at the center of the whirlpool is lower compared to the outer edges.

4. Factors Influencing the Whirlpool Formation:
- Flow rate: The rate at which water is flowing can influence the size and strength of the whirlpool. Higher flow rates can create larger and more powerful whirlpools.
- Obstacles or irregularities: The presence of obstacles or irregularities in the riverbed can disrupt the flow of water and contribute to the formation of whirlpools.
- Bottom topography: The shape and depth of the riverbed can also impact the formation and stability of whirlpools.

Conclusion:
The flow of water in a whirlpool of a river is an example of a free vortex. The water particles rotate in a circular motion around a central point, with the velocity decreasing as the distance from the center increases. Understanding the characteristics and formation of whirlpools can help in better understanding and managing river dynamics and hazards associated with them.