The form for the open boundary condition is shown in Open Boundary Condition Editor. In the Current Boundary Group Information frame the user may assign the Open Face Direction and Type of Open BC with drop down menus.
For open BC's, unlike flow BC's, the concentrations specified in the Constant Concentrations frame are always used for boundary assignments. The constant concentrations will be added to any time series concentrations defined. For example, if the user has a tidal time series of salinity that varies from 5 to 10 ppt and specifies a concentration for salinity of 10 ppt in the Constant Concentrations frame, EFDC will apply time variable salinity concentrations ranging from 15 to 20 ppt.
Figure 1 Boundary Condition Settings – Flow Boundary.
The Interpolation frame provides access to two functions:
- Assign generates new pressure series for the unassigned cells interpolated from the cells along the boundary that were assigned prior to pressing Assign. Interpolated series always have an ID that begins with "I:" to identify the series as an interpolated series. Each unassigned cell has its own interpolated series generated, then that series is assigned to that cell. Two or more prior assigned cells to existing series is required. The cells at either end of the open boundary must be defined for this process to work properly.
- Reset scans the current boundary group and finds any cells whose pressure series ID begins with "I:". If it finds cells with an interpolated series, it deletes the series and sets the pressure series index equal to zero (i.e. resets the assignment).