Full Equations (FEQ) Model for the Solution of the Full, Dynamic Equations of Motion for One-Dimensional Unsteady Flow in Open Channels and Through Control Structures
Purpose: The inflows and (or) outflows to or from within a branch of the stream system that can be localized to a point in, or at least a small section of, the stream are specified with this block. These flows might be water intakes for a city or a discharge point for a treatment plant. This block is present only when POINT=YES in the Run Control Block (section 13.1). In most cases, for robustness in model simulation, flows such as these should be input into a junction between branches instead of within a branch.
Heading: One line of user-selected information. The suggested string is POINT FLOWS.
LINE 1Variable: HEAD
Format: A80
Example: BRAN NODE TYPE TABN MFAC
Explanation: These are user-supplied headings for subsequent information.
LINE 2 (one for each point flow)Variables: BRA, NODE, TYPE, TABLE, MFAC
Format: 4I5, F10.0
Explanation:
Information for a point flow is specified on this line BRA is the branch number.Line 2 is given for each point flow. The same branch and node number may appear as many times as needed for multiple point flows in a given element. The end of the table is indicated by assigning a negative value for the branch number.NODE is the number of node on the branch at the downstream end of the element included with the point flow.
TYPE=1 and 2 for inflow and outflow, respectively.TABLE is the number of the table giving the flow as a function of time.
MFAC is the multiplying factor to apply to the flow to approximate the downstream component of momentum flux.
Specifying point flows is primarily done when the DTSF (appendix 2) is not used. The point flows referenced here can only be in a function table and not a file and, therefore, their duration is limited. The argument for function tables representing a time series is the elapsed time in seconds from the start of the analysis. A DTSF may contain several distinct nonoverlapping time periods to be simulated. The elapsed time is set to zero at the start of each period in the DTSF. Thus, any time series given in a function table will be reused for each time segment. Input and output files are a better means of specifying point flows for an extended period of time or with a DTSF.