SIC^2: Simulation and Integration of Control for Canals

Calculation settings

Louis Poirel — 2012-06-26T13:28:30Z

Calculation settings are available through the button or the Tools > Calculation settings menu.

Iteration parameters

Calculation at a section or a node use an iteration method (Newton or conjugate gradient). The user can define a maximum number of iteration and a precision.

If the required precision is not reached in the maximum number of iterations, the calculation will stop with an error warning : "Convergence problem in the section."

Simulation settings

Transient simulation

The first time-step of any transient calculation is calculated with the steady-state algorithm, in order to have an initial condition. If this option is unchecked, all time-steps are calculated in steady-state.

Text-dump of last time-step

When this option is activated, all data for the last time-step are written in a text file with fixed columns.

The file is created in the same folder as the XML project file, and is named [XMLFile's name]_FLUVIA.ALG or [XMLFile's name]_SIRENE.ALG depending on the hydraulic program used.

Le fichier sera crée dans le même dossier que le fichier XML et sera nommé NomDuFichierXml_FLUVIA.ALG ou NomDuFichierXml_SIRENE.ALG en fonction du calcul hydraulique utilisé.

Time

These parameters have the same definition as their hydraulic counterparts.

The beginning and end time of a simulation and the time-step are not necessarily the same for quality and hydraulic simulations :

is the time steps are different, hydraulic data used for quality calculation are interpolated ;
the actual simulated period will be the intersection of hydraulic and quality time period (cf. beyond).

Meteorological parameters

Louis Poirel — 2012-06-26T11:35:35Z

Meteorological parameters are entered by clicking on the button or through Tools > meteorological parameters :

In this windiw, the user can type in the following parameters :

Air Temperature
Air moisture (between 0 et 1)
Albedo (between 0 et 1)
Radiation (W.m^-2)
Wind velocity (m.s^-1)

All these parameter can vary with time.

Mask coefficients

The presence of tunnels or shade is raken into account through a mask coefficient between 0 and 1, accessible by clickink on the "Mask coefficient" button at the bottom of the Meteorological parameters window.

The user can then define these mask coefficient the same way as Strickler coefficients or infiltration data.

The mask coefficient is a constant, and shade varying with the angle of the sun during the day is not yet possible.

Boundary conditions

Louis Poirel — 2012-06-25T14:34:14Z

Drift quality classes simulated in ALGEQUEAU are transported from upstream to downstream, and the input concentrations are therefore needed.
Furthermore, the distribution at a node can be heterogeneous and requires the definition of a distribution coefficient. All these parameters can be set in through the boundary conditions window, accessible through the button or the Tools > Boundary conditions menu.

The first drop-down menu allows to choose on which type of network element we want to intervene :

Reaches : k on upstream and downstream (in case of flow-inversion) ;
Cross-structures : k ;
Node : k for infiltration in the pond ;
offtake : input (= boundary condition) for inflow and k for outflow.

The second menu allows the user to choose the element, and the third is for the quality class.

The user can then set the required parameters at the bottom of the window.

Distribution coefficients k may be adjustable in order to ensure mass conservation.

Exchange laws

Louis Poirel — 2012-06-25T13:15:24Z

A set of exchange laws should be defined to model the interactions between classes.

For each law, the user should click the "add a law" button, and then write a description, and select the type.

For instance, for the temperature evolution law, only one acting class should be defined, the temperature.

Initial conditions for fix classes

Louis Poirel — 2012-06-25T12:18:16Z

Initial conditions definition for fix classes is accessible through the quality classes definition window, with the "Edit the initial conditions of ..." button.

Initial conditions are defined the same way as Manning-Strickler coefficient or infiltration data in hydraulic mode : one value is given for a reach part, with the upstream and downstream limits abscissas for this reach part.

Definition of the quality classes

Louis Poirel — 2012-06-22T11:42:49Z

The definition of quality classes is accessible through the button or Tools > Quality classes definition.

One can add a new quality class with the "add a quality class" button.

Each quality class is given a name and a type. Depending on the type, different functionalities are available.

Drift quality classes

Drift quality classes such as nutrients, temperature, and drif algae or sediment must have boundary conditions on offtakes. Their initial condition is then obtained by a steady-state simulation.

Fix quality classes

Fix quality classes, which are not transported by the stream and only vary through user-defined exchange laws can be defined as fix sediment or fix algae. The channel geometry is modified according to the quantity of deposited or eroded sediment. For these classes, the user is invited to define the initial value.

Adding an Quality module to an hydraulic scenario

Louis Poirel — 2012-06-22T08:36:29Z

One Quality module can be created for each hydraulic scenatio.

When editing an hydraulic scenario, one can enter the Quality module by chosing «Quality module» in the Tools menu.

The next step is to define the quality classes.

The module can then be accessed through the project explorer if at least one quality class is defined. The module can also be deleted through the project explorer.

Presentation

Louis Poirel — 2012-06-22T08:03:30Z

The ALGEQUEAU module adds quality simulation capabilities to FLUVIA and SIRENE. It was first developed to medel algal development in irrigation networks.

An hydraulic scenario may not contain more than one ALGEQUEAU module, but hydraulic data used for quality simulation can come from any variant of this scenario.

The first step when building a quality simulation is to define the quality classes, which may be :

a temperature (°C) ;
a nutrient concentration (mg/L) ;
a concentration of drift algae (kg/m3) ;
a linear density of fixed algae (kg/m)
a sediment concentration in water (g/m3) ;
a linear density of sediment in the bed (m3/m).

Their evolution is ruled by transport and exchanges, following exchange laws depending on hydraulic and quality parameters.

For now, the module can :

transport temperature, nutrient, drift algae and sediments along the stream, following the transport equation ;
calculate at a section the exchanges between classes ;
calculate at a node the downstream repartition of transported classes.