Distinguish, differentiate, compare and explain what is the difference between Free Surface and Pipe Flow.
Difference between Free Surface and Pipe Flow
- Open channel flow can be defined as a passage in which liquid flows with its upper surface exposed to atmosphere. A pipe is a closed conduit which is used for carrying fluids under pressure.
- Open channel flow is due to gravity and its conditions are greatly influenced by slope of the channel. The flow in a pipe is termed as pipe-flow only when the fluid completely fills the cross section & there is no free surface of fluid.
- In the first, the hydraulic grade line coincides with the water surface while in th other hydraulic grade line does not coincides with the water surface.
- In the free surface maximum velocity occurs at a little distance below the water surface. In the pipe, maximum velocity occurring at the pipe centre.
- In the free surface shape of the velocity profile is dependent on the channel roughness while in the other the velocity distribution is symmetrical about the pipe axis.