Identifying laminar and turbulent flow can be done using different experiments. These methods help us see the unique features of each flow type.

1. Flow Visualization:
One easy way is to add a dye or a tracer to the liquid.

• In laminar flow, the dye moves in smooth, layered paths without mixing.
• In turbulent flow, the dye spreads out quickly and randomly in the liquid.

2. Smoothness vs. Roughness:
The surface texture of pipes affects the flow type.

• Laminar flow usually happens in smooth pipes.
• Turbulent flow happens in rough or uneven surfaces.

By watching how the flow changes from laminar to turbulent, we can learn a lot about the flow's behavior.

3. Reynolds Number ($Re$):
This number helps us classify the flow. It’s calculated using this formula:

$$Re = \frac{\rho v D}{\mu}$$

In this formula:

• $\rho$ is the fluid's density,
• $v$ is the speed of the flow,
• $D$ is the pipe's diameter, and
• $\mu$ is the fluid’s thickness.

If $Re < 2000$, the flow is usually laminar. If $Re > 4000$, the flow is turbulent.

4. Pressure Drop Measurements:
Watching how pressure changes in a flow system can also help identify the type.

• If you see a straight (linear) change in pressure, it's likely laminar flow.
• If the change is uneven (nonlinear), it usually means there’s turbulence.

In short, by using these methods—flow visualization, looking at surface textures, calculations of Reynolds number, and checking pressure changes—we can tell if the flow is laminar or turbulent in a clear and effective way.