Hydrology Module 7 Flashcards Open Channel Flow

culvert

covered channel flowing usually partly full

Artificial channel examples

-flumes - spillways - canals -weirs - drainage ditch -culverts

Natural Channel examples

-streams - rivers - flood plains

chute

Channel with a steep slope

Drop

Channel with a sudden change in elevation

Froude Number =1

Critical Flow

Open Channel Flow

Flow of liquid in a conduit with free space (interface between water and air) - Applied to understand the flow of a liquid in : 1. Artificial channel : and 2. Natural channel:

Froude number <1

Subcritical Flow -quiet

Froude Number > 1

Supercritical Flow - Rapid

Darcy-Weisbach equation

Theoretically based equation developed for determining head losses in pipes adapted to open channel flow

Reynolds number > 1000

Turbulent Flow

State of flow

Varies with viscous, internal and gravitational forces - can be laminar or turbulent Determined by the Reynolds and Froude number

Laminar Flow

Viscous forces dominate over inertial forces

Canal

a long and mild-sloped channel built in the ground

Natural Channel

has irregular geometry throughout

Turbulent Flow

inertial forces predominate over viscous forces

Reynolds number < 500

laminar flow