CE 3372 Water Systems Design

Pipe Networks

Networks

• Spreadsheet Example– Representative of a “by-hand” solution.

• EPA NET Program Introduction– Representative of a “professional-type program”

solution.

Networks – Why Model?

• What is the flow distribution if the demands are changed as shown?

0.1 cfs

0.4 cfs

Sketch and Label

Node-Arc Incidence Matrix

Energy Losses in Loop

• Determine “sign” for loop equations from loop traverse direction and assumed flow directions.

Build a Computation Tool

What If?

• Once the tool is built, then “what-if” questions can be posed (as per example).– Next repeat the exercise using EPA-NET

Networks

• EPA Net (Computer Program)– Performs extended period simulation of hydraulic

and water quality behavior within pressurized pipe networks.

– Provides an integrated environment for editing network input data, running hydraulic and water qresults in a variety of formats.

Networks

• EPA Net (Computer Program)– Computes friction head loss using either Hazen-

Williams, Darcy-Weisbach, or Chezy-Manning equations. Includes minor head losses for bends, fittings, etc.

– Models constant or variable speed pumps.– Computes pumping energy and cost.– Models various types of valves including shutoff,

check, pressure regulating, and flow control valves

Networks

• EPA Net (Computer Program)– Allows storage tanks to have any shape (i.e.,

diameter can vary with height).– Considers multiple demand categories at nodes,

each with its own pattern of time variation – Models pressure-dependent flow issuing from

emitters (sprinkler heads) – Base system operation on both simple tank level

or timer controls and on complex rule-based control

Networks

• EPA Net (Computer Program)– EPANET models a water distribution system as a

collection of links connected to nodes. • The links represent pipes, pumps, and control valves.• The nodes represent junctions, tanks, and reservoirs.

Networks – Why Model?

• Illustrative Example:– What is the flow distribution if the demands are

changed as shown?

0.1 cfs

0.4 cfs

Example in EPA NET

• Install and open EPA-NET – How to install on the server as a movie.

• Create a new project – Ce3372_epanet_example1

• Check defaults.• Import the backdrop (optional)