Stream line flow (laminar flow) and turbulent flow

Stream line flow (laminar flow) and turbulent flow

Stream line flow (laminar flow)

To maintain the flow of a liquid through a tube, some pressure should be given at one end of the tube to overcome the viscous drag. For a given external pressure, the velocity of flow depends on the coefficient of viscosity. At low pressure the velocity is less than a certain velocity called the critical velocity and the liquid flows in an orderly manner and the flow is called steady flow or streamline flow.

In stream line flow,

1. The liquid particles flow in an orderly manner. i.e., the liquid particles flow along straight lines, each line is called the line of flow.

2. The lines of flow are parallel to the axis of the tube.

3. The velocity of all particles in a line of flow is a constant.

4. The velocity of flow is always less than the critical velocity.

5. Stream line flow will happen only when the driving pressure is small.

6. The flow of water through a capillary tube at the rate of five to six drops per minute is an example for stream line flow.


Stream line flow (laminar flow)
Stream line flow (laminar flow)

Turbulent flow

When the external pressure causing the flow of the liquid is high, the flow of the liquid is said to be turbulent.

In turbulent flow,

1. There is no orderliness in the flow of liquid.

2. The liquid particles will not flow along straight lines, but will flow in curved paths in a zig-zag manner.

3. The different particles of the liquid will flow in different directions with different velocities.

4. The velocity of flow is always greater than the critical velocity.

5. Turbulent flow will happen when the driving pressure is high.

6. The flow of water from a tap is an example for turbulent flow.

turbulent flow
Turbulent flow



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