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Model Data Structure


A model can contain up to 100 sub-systems to aid the construction and maintenance of large, complicated models.  For example, separate sub-systems could be created for a city's raw surface water assets, raw ground water assets, water treatment facilities, and treated water distribution.

Within a model of a treatment plant, each process module could be managed as a separate sub-system.

System Components

A sub-system is an assembly of the following types of objects:

Primary physical assets:

  • pipes;
  • tanks;
  • valves;
  • pumps;
  • sprinklers;
  • chemical dosing points; and
  • node junctions - where assets connect.

Notional objects:

  • consumption/demand - from a node on the model;
  • head points - pre-defining variation in hydraulic level at a point; and
  • bore drawdown - defining how an aquifer responds to abstraction flow rate.

Physical assets for surge protection:

  • air cushions;
  • air valves:
  • anti-vacuum valves;
  • pressure relief valves:
  • pressure vessels:
  • stand pipes: and
  • surge tanks.

Notional devices for transient simulation:

  • dummy long mains - to simplify some pipe networks.
Global Characteristics

The following parameters apply globally across all sub-systems in a model:

Demand characteristics

  • types of consumption/demand; and
  • their variation over time.

Pipe library

  • pipe material characteristics;
  • pipe classes; and
  • sizes available within a pipe class.

Valve characteristics

  • a set of valve build types; and
  • variation of headloss with valve opening position.

Pump characteristics

  • a set of generic pump types;
  • variation of head versus flow rate and speed; and
  • variation of torque versus flow rate and speed.

System control logic

  • control blocks;
  • definintion of instruments and controlled devices; and
  • operational logic.

Electricity price tariffs

  • pricing parameters; and
  • time of day and periodic usage charges.

Source water quality characteristics

  • a single type of source water;
  • its first order decay characteristics; or
  • initial concentrations and decay rates of multiple impurities in the source water.