Types of flow
The type of flow is an important factor when considering energy loss within a hydraulic circuit.
There are two different types of flow:
- Laminar flow;
- Turbulent flow.
The type of flow may be determined using Reynolds number.
Reynolds number is dependent on the velocity of flow, viscositi of a liquid and on the cross-sectional area throught which flow occurs.
Laminar flow
Up to a certain velocity, friction forces dominate, the Reynolds number is small. Liquid move along pipes in layers. The inner-most liquid layer at the pipe surface does not move. The outer-most liquid layer at the pipe surface does no movie.
![Laminar flow Laminar flow](https://www.hydraulic-calculation.com/images/upl/10_28_18_16_20_21_Laminar.jpg)
Laminar flow occurs for Re<2300.
Turbulent flow
If the velocity of flow is increased, inertial forces begin to increase in the flow, at the critical velocity the type of flow changes from laminar to turbulent.
![Change fro laminar to turbulent flow Change fro laminar to turbulent flow](https://www.hydraulic-calculation.com/images/upl/10_28_18_16_20_51_Laminar_turbulent.jpg)
When inertia forces dominate the flow, the flow becomes whirling. The flow resistance increases and thus the hydraulic losses increase. This is the turbulent flow.
![Turbulent flow Turbulent flow](https://www.hydraulic-calculation.com/images/upl/10_28_18_16_24_20_Turbulent.jpg)
Turbulent flow is not usually desirable, because the hydraulic losses increase.
Turbulent flow occurs for Re>2300.