West 2009

Prime tools for modeling and simulation in water quality

WEST® 2009 is the new (and long awaited) generation of WEST®.
The first release is called WEST® 2009a and was officially release on November 5th 2009.
WEST® 2009 renovates the 'old' WEST® concept in at least three ways.

1. It consists of a suite of products, as opposed to the previous concept of modules (e.g. Configuration, Simulation, etc.) in which each module corresponded to a specific set of functionalities.
The different products of the new suite are aimed at specific applications (e.g. WESTforDESIGN is especially suited for (pre)design modeling) and therefore contain a different set of tools, have different features, enable a different degree of flexibility, etc. that are appropriate for a given application.
2. The graphical user interface of WEST® 2009 is fully integrated: the separate applications that WEST® used to consist of, e.g. the Configuration Builder and the Experimentation Environment, are now integrated into one single application. This has a considerable impact on a number of aspects, as it will be illustrated in the follow up.
3. A fair amount of new features has become available with WEST® 2009, many of which have been requested by WEST® users.
Possibly the most relevant new features are: the influent generator, the introduction of layers in the model layout and uncertainty analysis.

NEW FEATURES

The Influent Generator
The Influent Generator (in fact termed: Influent/Effluent Generator, as the same concept applies to the Effluent of the plant) is a tool incorporated in the main WEST® environment primarily aimed at assisting the user in generating a suitable input file for the model.
This may be quite a long, tedious, activity since data for the characterization of the influent may be only partially available, may come from different sources and/or may prove not sufficiently reliable; also, determinations of the influent characteristics are typically conducted with reference to conventional quantities rather than directly with reference to the specific model components (variables).
A Fractionation Model is therefore needed between the two sets of variables which translates the custom units into model units.
To provide an approach consistent with the overall concept of building a model graphically, by arranging unit icons and establishing connections between them, the Fractionation Model is to be constructed graphically by means of the Influent Generator Tool.
On the opposite end of the Plant Layout, the characterization of the effluent is typically expressed with reference to the same custom units that are used to characterize the influent to the plant and as concentrations (for it is to be compared against environmental Standards); so that the transformation opposite to the one carried out on the Input Unit, is to be carried out on the Output Unit, that is a De-fractionation Model.
Access to the Influent/Effluent Generator is through the influent and the effluent wizards.
The layers
A plant layout can be set up making use of layers, that is: assigning each Process Unit to one of the three default layers (i.e. Water line, Control and Sludge line).
Layers may be independently visualized by (de)selecting the respective Visibility option.
Irrespectively of the Layer to which a Process Unit is associated, the overall model will evidently treat all units as part of the same general layout.
New process icons and additional graphics elements
The 'old' set of Process Nodes of WEST® 3.7.6 has been replaced by a completely new set on Nodes: emphasis has been given to a closer resemblance to the actual unit process (see Figure) that may be more appropriate for inclusion of the plant layout generated in WEST® directly into technical reports.
Notable improvement in respect to WEST® 3.7.6 are that Process Node can be resized (e.g. to visually match the relative size of unit processes on the plant) as well as moved and rotated in a variety of ways.
The new design was done by Mariana Koleva of the University of Architecture, Civil Engineering and Geodesy of Sofia (Bulgaria).

In the same direction, of allowing for a plant layout that can be more visually appealing and that can perhaps be more easily integrated into technical documentation, graphic elements such as text, frames and pictures can be added to the plant layout (see Figure).
New concept for the generation of executable models
In WEST® 2009 one is able to define simulation experiments as soon as process units are dropped on the Layout Editor's canvas, without having to first create an executable model
This approach primarily ensures that the Plant Model is set up in the most efficient and flexible way.
It is also very convenient as it enables accessing the model properties (parameters and variables) while the model layout is being constructed - which in turns enables setting the parameter values and creating input and output objects (i.e. sliders to change parameter values and plots and tables to view the output of the simulation) while the model layout is being constructed.
Miscellaneous new features

» Compatibility with the earlier version of WEST® (3.7.6) is ensured through a Project Import functionality
» All model categories include temperature variation, by default
» The description of biomass decay of ASM2d has been improved: the new model is termed ASM2dMod (quote)
» Energy calculation is now incorporated in all relevant models
» At the end of the steady-state simulation, all models are automatically re-initialized (so that the dynamic simulation can be started immediately)
» An automatic detection of the steady-state has been implemented
» An "Info pane" has been introduced that display the relevant information (e.g. parameter values) for the currently selected Process Unit
» No need for (flux/concentration) unit conversion by means of specific units in the layout

THE PRODUCT SUITE

WEST® 2009 comprises the following products.

WESTforDESIGN
Advanced dynamic modeling and simulation to enhance the design process
WESTforDESIGN allows for validation of design options and evaluation of different plant layouts (including control strategies). This is done by running scenarios and evaluating their performance according to user-defined criteria.
WESTforOPERATORS
Easy-to-use dynamic modeling and simulation to assist operational decisions on the plant
WESTforOPERATORS enables the operator to perform short-term (e.g. storm events) and long-term (e.g. consistent nutrient removal) evaluations of their plant. The evaluations (e.g. for bottleneck identification) are carried out by running scenarios for specific influent and operational conditions and costs evaluation. The tool is also useful to improve understanding of the WWTP and hence for operator training.
WESTforOPTIMIZATION
Cutting-edge dynamic modeling and simulation to support WWTP process optimization
WESTforOPTIMIZATION enables consultants and engineers to optimize the wastewater treatment processes. With its flexibility and fully open model structure (one can change any model in the model library without limitations) in combination with specific tools for easier model calibration and plant performance evaluation (sensitivity analysis, parameter estimation, scenario analysis and uncertainty analysis) and for minimization of objective functions (e.g. costs).
WESTforAUTOMATION
Seamless integration of dynamic modeling and simulation in your WWTP process automation applications
WESTforAUTOMATION allows for fast integration of modeling and simulation in custom applications by automation or software engineers. Different SDKs containing comprehensive and extensive documentation and sample sets, allow for linking WEST with SCADA systems or other modeling software (e.g. for CFD, for sewer modeling).
WESTforIUWS
Powerful dynamic modeling and simulation for your Integrated Urban Water Systems (sewer, WWTP, river)
WESTforIUWS enables the exploration of scenarios developed by the consultant or system manager (e.g. flow diversions, introduction of tanks, changes in operation, etc.) with regard to water quality and quantity; automatic optimization of the operating parameters; short- and long-term evaluations; uncertainty and sensitivity analysis of the model to identify the most influential operating parameters and to assess the risk of non-compliance with regulations.
WESTforCLUSTERS
Lightweight distributed execution of computationally intensive virtual experiments
WESTforCLUSTERS is a lightweight distributed execution system that allows for distributing the workload generated by some of WEST's computationally intensive virtual experiment types (typically scenario and Monte Carlo analysis) over a number of (idle) work nodes (PCs). The software consists of a Master component that processes job descriptions and assigns them to work nodes. Each of these work nodes is equipped with a Slave component that accepts job descriptions and executes them as a background task.