Wadiso 6 User Guide > Time/Water quality simulation

Extended period time simulation of pipe networks serves three important functions. First, instead of only providing a snapshot of system performance under some rather arbitrary condition, it will provide a time-based history of such system performance. Of particular interest are pressure fluctuations in low pressure areas, and pressure response to fire flows and pipe breaks. Secondly, extended period time simulation is required for the reliable sizing of water storage tanks. To keep such simulation realistic, it is necessary to model not only varying demand patterns in residential, industrial and commercial areas of the network, but also the rather complex schemes by which the pumps and valves in the system are operated and controlled. Control of pumps and valves by means of pressure sensors in critical areas of the network, by water level in storage tanks, as well as time (to take advantage of low-cost energy periods), can all be modelled. Thirdly, the extended period time simulation can be utilized to model water quality criteria, such as the growth/decay of chemical constituent in the system, water age, and/or the tracing of water originating from a specific source.

A Time/WQ Simulation basically consists of:

•entering/editing data and parameters for the Time/WQ Simulation,

•performing the Time/WQ simulation,

•and finally viewing the results.

Time/WQ Simulation requires considerable amounts of additional data, over-and-above that which is required for steady state analysis. It is therefore important to study the sections on Time Simulation Technique & General concepts, Definition of Time/WQ terms, and Time/WQ Data, in order to fully comprehend this feature of the program, and to be able to take full advantage of all the options.

For those time/WQ simulation parameters which are related directly to elements of the system model, an alternative means for input and editing of time/WQ simulation data is presented. Furthermore, the storage of time/WQ simulation data will be discussed.

Finally, a typical Time/WQ Simulation session is demonstrated and the Time Simulation of Existing System example is included in the Tutorial to illustrate the Time/WQ Simulation features of the program.