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Simulation Objects
The following enhancements to the RiverWare simulation objects are described briefly. The user is encouraged to consult the Simulation Objects Documentation in the online help for more detailed descriptions of the enhancements to the objects and their methods.
Data Objects Now Have Different Colors
A new enhancement to the Data Object allows the user to set the color of the object. The Data Object’s color can be set by selecting Edit->Set Icon Color from the Open Object dialog.
Inline Power
The Inline Power object was enhanced to include the following general slots: Turbine Release, Max Turbine Release, Plant Capacity Fraction, Bypass, Min Bypass, and Hydro Capacity. The addition of the Max Turbine Release slot will cause existing models (that use the Inline Power object) to abort. A Max Turbine Release value must be input in order to fix the model. The user should be aware that the units for all of the new slots will be standard RiverWare units and users must configure them accordingly.
The Turbine Release, rather than the Inflow, is now used for the power calculation. The Plant Capacity Fraction is used when the plant is not operating at full capacity. The Bypass slot is set to a user input Min Bypass value plus the spill. A new dispatch method, solveMB_givenOutflow was added to allow the object to solve upstream. A new method category, called Solution Direction, was added to allow either upstream and downstream solving, or solving in the downstream direction only.
Also, methods for calculating spill cost and turbine ramping cost were included for use in optimization models.
Reach
Negative Outflow Warnings Removed
Prior to this release, if a reach object computed a negative outflow it would print a warning message to the diagnostics window. In Rulebased Simulation models, reaches often solve several times per timestep. While some of these solutions may result in a negative outflow, the final result is usually a positive outflow. This results in several warning messages that are insignificant because the final answer is not negative. Furthermore, these messages clutter the diagnostics window and are generally annoying. In RiverWare 4.1 these warning messages have been removed. Since most users ignored these messages for the reasons given above, this is generally not a problem. However, if some users were relying on these warning messages to catch modelling errors, they need to be aware of this change and find this information some other way.
GainLoss Methods with Time Lag Routing
Two of the GainLoss Calculation methods on the Reach object, Seasonal GainLoss Flow Table and Interpolated Flow GainLoss, are no longer valid methods when Time Lag Routing is the selected routing method on the reach. The reason for this change is that it is impossible to get the same answers solving upstream and downstream when using Time Lag Routing with one of these loss methods. Therefore, we disabled these two methods when Time Lag Routing is selected. If an existing model has a reach with both Time Lag Routing and one of the two loss methods mentioned above, RiverWare will give the following warning message when loading the model in the 4.1 release: “The <loss method name> method is no longer available when using timeLagRouting. You will need another reach to do the Gain Loss calculations. ...” If this happens, the GainLoss method on the reach in question will be changed to No GainLoss. You will need to create a separate reach object to do the Gain Loss calculations.
Reservoir
Plant Power Equation
A new method, Plant Power Equation, has been added to the Power Calculation Category. This method computes power based on the Water Power Equation:
where power is the plant power, turbine release is the flow through the turbines, H is the net head across the turbines, e is the plant efficiency expressed as a decimal percentage, and the Power Plant Capacity Fraction is the fraction of full capacity at which the plant is operating.
Peak Power Equation
A new method, Peak Power Equation, has been added to the Power Calculation Category. This method computes power based on the Water Power Equation:
where power is the plant power, peak flow is the peaking flow rate through the turbines, H is the net head across the turbines, e is the plant efficiency expressed as a decimal percentage, and the Power Plant Capacity Fraction is the fraction of full capacity at which the plant is operating. Once the peak flow and the power have been determined, the method computes the peak time. This is the amount of time the turbines were running at peak power.
CurrentSurfaceAreaPanAndIce
A new evaporation method, called CurrentSurfaceAreaPanAndIce, has been added to all reservoir objects. This evaporation method is identical to the PanAndIceEvaporation method except that is uses the current surface area instead of the average surface area.
Input Bank Storage
A new method, Input Bank Storage, was added to the bankStorageCalcCategory on all reservoir objects. This method allows the user to input a time series range of bank storage values.
AggDistribution Canal Elements
Input Seepage
A new method, Input Seepage, was added to the Canal Seepage category on Distribution Canal Elements. This method allows the user to input the seepage losses from the canal elements.
Revised: 08/04/2020