Parallel Streamlines in a Flow

When the streamlines of the particles in a flow are parallel to each other, it indicates a specific type of flow. In this case, the correct answer is option 'C', which is a uniform flow. Let's understand why this is the correct answer in detail.

Uniform Flow
A uniform flow refers to a flow in which the velocity of the fluid at any given point remains constant over time. In other words, the flow is steady and does not change in magnitude or direction. This type of flow is characterized by parallel streamlines.

Explanation
To understand why parallel streamlines indicate a uniform flow, let's consider the definition of streamlines. Streamlines represent the instantaneous paths followed by fluid particles as they move through a flow field. These lines are tangent to the velocity vectors at every point.

- When the streamlines are parallel, it means that the direction of fluid motion is the same along each streamline.
- Since the flow is parallel, there is no change in direction or magnitude of velocity as we move along the streamlines.
- This indicates that the fluid particles are moving uniformly, without any variation in velocity.
- In such a flow, the fluid particles maintain a constant distance from each other, and there are no regions of acceleration or deceleration.
- This uniformity in the flow results in the parallelism of streamlines.

Other Flow Types
Let's briefly discuss the other options to understand why they are not the correct answers:

- Steady Flow (Option A): Steady flow refers to a flow in which the velocity at any given point remains constant with respect to time. Steady flow can have streamlines that are parallel or non-parallel, so it is not the correct answer in this case.
- Unsteady Flow (Option B): Unsteady flow refers to a flow in which the velocity at any given point changes with respect to time. In an unsteady flow, the streamlines can be parallel or non-parallel, so it is not the correct answer in this case.
- Non-uniform Flow (Option D): Non-uniform flow refers to a flow in which the velocity of the fluid changes in magnitude or direction at different points in the flow field. In a non-uniform flow, the streamlines can be parallel or non-parallel, so it is not the correct answer in this case.

Therefore, the correct answer is option 'C', which represents a uniform flow characterized by parallel streamlines.