This method calls the utility method solveTimeLagTemp.

This method calls the utility method solveTimeLagOutSalt.

This method calls the following utility methods:

This method calls the following utility methods:

This method calls the following utility methods:

This method calls the utility method solveVarTimeLagOutSalt.

This method calls the following utility methods:

This method calls the following utility methods:

This method calls the following utility methods:

This method calls the following utility methods:

This method calls the following utility methods:

This method calls the following utility methods:

This method solves for water temperature based on control volume mass balances. The numerical solution to the convection-diffusion equation is an explicit backward difference. To prevent instabilities, a user input maximum flow rate is required so that the water quality algorithm will maintain stability regardless of the simulation time step. This is accomplished by calculating the time step required for numerical stability based on a conservative substance. Although the mass balance for water temperature includes transformation it is assumed negligible for the stability of the solution. If the required time step for stability is less than the simulation time step, the algorithm is executed multiple times at a time step less than or equal to the required time step. The total time of these steps will cumulatively equal the simulation time step. If the user defined maximum flow is not exceeded in the simulation, the solution will remain stable.

This method calls the following utility methods:

The basic methodology of the controlVolumeImplicit method is no different than the controlVolumeExplicit method, with the exception of the solution technique being an implicit backward difference approximation to the convection equation. Longitudinal dispersion is not included in this method to decrease to computational effort in obtaining a solution. This numerical solution is unconditionally stable and does not require that a maximum flow rate be input by the user.

This method calls the following utility methods:

This method solves for salt concentration based on control volume mass balances.

This method calls the following utility methods:

The basic methodology of the controlVolumeImplicit method is no different than the controlVolumeExplicit method, with the exception of the solution technique being an implicit backward difference approximation to the convection equation.

This method calls the following utility methods:

This method solves for salt concentration and water temperature based on control volume mass balances. The numerical solution to the convection-diffusion equation is an explicit backward difference. To prevent instabilities, a user input maximum flow rate is required so that the water quality algorithm will maintain stability regardless of the simulation time step. This is accomplished by calculating the time step required for numerical stability based on a conservative substance. Although the mass balance for water temperature includes transformation it is assumed negligible for the stability of the solution. If the required time step for stability is less than the simulation time step, the algorithm is executed multiple times at a time step less than or equal to the required time step. The total time of these steps will cumulatively equal the simulation time step. If the user defined maximum flow is not exceeded in the simulation, the solution will remain stable.

This method calls the following utility methods:

The basic methodology of the controlVolumeImplicit method is no different than the controlVolumeExplicit method, with the exception of the solution technique being an implicit backward difference approximation to the convection equation. Longitudinal dispersion is not included in this method to decrease the computational effort in obtaining a solution. This numerical solution is unconditionally stable and does not require that a maximum flow rate be input by the user.

This method exists to instantiate the appropriate slots. All of the calculations are performed in the dispatch method. The following dispatch methods are available when Mass Balance Salinity is selected:

When the reach is an element of an Agg Reach, the aggregate controls the method selection on the elements. For Well Mixed Salt, the reaches can either model None or Mass Balance Salinity. When Mass Balance Salinity is selected on the aggregate, then this method is selected on the reach but is invisible. The routing method must be No Routing or an error will be issued. See None and Mass Balance Salinity for details.

The reach routes the TDG concentration:

The reach routes the TDG concentration using a simple lag:

The reach routes TDG with three components: Lag Time, Dispersion and Dissipation. First the TDG Lag Time and Dispersion are applied together. The Dispersion Coefficients are applied on the lagged TDG concentration.

The Offset and Coeff come from the first and second columns respectively of the TDG Dispersion Coefficients table slot.

Next the TDG Dissipation is calculated if it is not specified (input or rules). If TDG Dissipation is specified, this step will be skipped.

If TDG Dissipation Adjustment is not specified, it will default to zero. The TDG Dissipation Coefficient is applied to the TDG concentration above 100 % saturation.

Finally, the Outflow TDG Concentration is calculated as