Enhancements and Modifications to the Full Equations (FEQ) Model,
March 1995 to August 1999
Note: This document is separate from the U.S. Geological Survey report by Franz and Melching (1997). This description of enhancements and modifications to the Full Equations Utilities Model has not been approved by the Director of the U.S. Geological Survey.
Input description update for section 13.12 Operation of Control Structures Block-- Operation Tables, Franz and Melching (1997a), p. 187
Section 13.12 Operation of Control Structures Block--Operation Tables
Purpose: The operation rules for any dynamically operated control structures are given with this block. This block is only required if SOPER=YES in the Run Control Block (section 13.1). The maximum number of Operation-Control Blocks allowed in FEQ is specified in the parameter MNBLK in the INCLUDE file ARSIZE.PRM (appendix 3). This number may be increased as necessary and FEQ recompiled.
Heading: One line of user-selected information. The suggested string is OPERATION OF CONTROL STRUCTURES.
LINE 1
Variable: | BLK |
Format: | 4X, I5 |
Example: | BLK=00001 |
Explanation: |
Gives the number of the operation-control block table. BLK1 terminates input of operation blocks. Operation-control block tables must be numbered consecutively from 1. |
LINE 2
Variable: | BLKTYP, SPEEDS |
Format: | 8X, A8, 1X, 7X,I5 |
Explanation: |
Gives the type of the operation-control block and the number of discrete speeds that a multi-speed pump can have. Making the speed range discrete avoids having the pump operate at a physically unrealistic speed during its operation. If the number of speeds is 4, then the pump speeds are: 0.0, 0.25, 0.50, 0.75, 1.00. There are three types of operation blocks: BLKTYPE=PUMP denotes that a one-way pump is being controlled, BLKTYPE=PUMP2WAY denotes that a two-way pump is being controlled, and BLKTYPE=GATE denotes that a gate is being controlled. |
LINE 3
Variable: | MINDT |
Format: | 6X, F10.0 |
Example: | MINDT=300. |
Explanation: |
Gives the minimum time that must elapse between changes to the gate or pump setting. Changes in the setting can only occur at the boundary between time steps but at least MINDT seconds must have elapsed since the last change before the next change can be made. |
LINE 4
Variable: | PINIT |
Format: | 6X, F5.0 |
Example: | PINIT=0.62 |
Explanation: |
Initial value for the opening fraction. The opening fraction varies between 0 and 1. When PINIT=0, the gate is completely closed (underflow gates: sluice gates, tainter gates, and so forth), or in the fully raised position (overflow gates: drum gates and related devices). The gate is so positioned to either force the flow to zero or reduce it to a minimum value. When PINIT=1.0 the gate is positioned such that the flow is given its maximum value for the given water-surface elevation. For a pump the values gives the speed of the pump relative to the standard speed chosen for the table defining the relationship between flow and head for the pump. The pump is off when PINIT=0.0 and the pump is on at the relative speed given if PINIT0. |
If BLKTYPE=GATE (Gate Operation)
LINE 5
Variable: | HEAD |
Format: | A80 |
Explanation: |
User supplied headings for subsequent information. |
LINE 6
Variables:
BRA,
NODE, KEY, MODE, MNRATE, ML, LL, LU,
MU, LPRI, NPRI, HPRI, DPDT
Format:
I5,
2A5, I5, 5F7.0, 3I5, F5.0
Explanation: |
Specifies the parameters defining a control point used in the operation of a structure. The values are: |
BRA is the branch number for the control point. BRA0 if the node is an exterior node. BRA0 denotes the end of input for the current block.
NODE is the node label for the control point.LINE 6aKEY is the ELEV if control point senses water surface elevation, KEYQCON if control point senses flow rate and the null zone limits are constant values, KEYQVAR if the control point senses flow rate and the null zone limits are variable, and KEYnew style exterior node label if water-surface elevation difference is being sensed. The null zone is that range of the sensed value (flow, elevation, or elevation difference) in which the setting of the structure will not be changed. If elevation difference is selected the difference is taken in the sense of elevation at node in NODE less the elevation at node in KEY.
MODE0 means that the structure opening is changed whenever the value being sensed at the control point is outside the null zone. MODE1 means structure opening is changed only if the value being sensed at the control point is outside the null zone and is not moving in the right direction with sufficient speed.
MNRATE is the minimum change per hour under MODE1 required to avoid changing the structure opening. For example, if KEYELEV indicating that water-surface elevation is being sensed and if MNRATE0.01 then the elevation at the sensing point must be moving toward the null region at a rate exceeding 0.01 foot/hour to avoid having the structure opening changed.
ML is the rate factor for the rate of change of opening when the control point is below the null zone. This rate factor is a multiplier on the distance that the sensed value is from the closest boundary of the null zone. The resulting rate is the change per hour of the structure opening as measured by an opening fraction,, which is taken as 0.0 when the structure opening is such as to restrict the flow by the maximum amount and as 1.0 when the structure opening is such to restrict the flow by the minimum possible amount. The actual rate of opening used is limited by DPDT, given later in the input. Note that the rate factor sign is determined by the location of the control structure relative to the control point as well as the goal of the control structure.
LL is the lower limit for the null zone.
LU is the upper limit for the null zone.
MU is the rate factor for the rate of change of opening when the control point is above the null zone.
LPRI is the numerical priority of the action for this control point when the sensed value is below the null zone. Numerical priority 1 is the highest priority, 2 is next, and so forth. The numbers are ordinal only, that is, used only for relative ranking. There is no degree of priority difference so that the only relationship used is the quality of being equal, being greater than, or being less than.
NPRI is the priority of the action for this control point when the sensed value is in the null zone.
HPRI is the priority of the action for this control point when the sensed value is above the null zone.
DPDT is the absolute value of the maximum permitted rate of change in the opening fraction for the structure.
When KEY is the QVAR an additional two lines of input are required. The first line gives headings and the second line the values required to define the variable null zone.
Variable: HEAD | |
Format: A80 |
Explanation: |
User supplied headings for subsequent information. |
LINE 6b
Variables:
NUMB,
NZHW, (NDVEC(J), NDWT(J), J=1,NUMB)
Format:
I5,
F5.0, 7(I5,F5.0))
Explanation: |
Specifies the values required to define the variable null zone limits. The meaning of the values is: |
NUMB is the number of exterior nodes to use in computing the flow to define the mid-point of the null zone.
NZHW is the null zone half width. The null zone half width is added to the mid-point flow for the null zone to give the upper limit of the null zone. It is subtracted from the mid-point flow to give the lower limit.If BLKTYPE=PUMP (Pump Operation)
NDVEC contains the NUMB exterior nodes used to compute the mid-point of the null zone.
NDWT contains the weight to use for each exterior node's flow in computing the mid-point of the null zone. This weight can be positive or negative. The weight on the exterior node flows can be used to deduct flow which leaves the system by some other route than the structure being operated by this control block. Also the weight can be used to account for other sources of inflow, such as diffuse inflow not reflected by any exterior node. As the heading indicates, the exterior node and its associated weight are given pairwise in the input.
LINE 5
Variable: HEAD | |
Format: A80 |
Explanation: |
User supplied headings for subsequent information. |
LINE 6
Variables:
BRA,
NODE, KEY, MNRATE, RISE, FALL,
ONPR, OFPR
Format:
I5, 2A5, F7.0, 4I5
Explanation: |
Specifies the parameters defining a control point used in the operation of a potentially variable speed pump. The values are: |
BRA is the branch number for the control point. BRA0 if the node is an exterior node. BRA0 denotes the end of input for the current block.Line 6 is repeated for each control point given for each table. The auxiliary lines, 6a and 6b for KEYQVAR must also be repeated in sequence. A table is terminated by a negative branch number. Input of tables is terminated by a negative value for BLK.
NODE is label for the node at control point.
KEY is the ELEV if control point senses water surface elevation, and KEYQCON if control point senses flow rate. The nature of pump control does not permit using a variable width null zone as for gates when KEYQVAR is specified. The null zone is that range of the sensed value (flow or elevation) in which the setting of the pump will not be changed.
MNRATE is the minimum change per hour in the sensed variable (flow or elevation) required to change the table defining the pump operation. There are two pump operation tables possible: one for a rising level at the control point and one for a falling level. The level must have been moving at least as fast on the average as the rate given in MNRATE before FEQ decides that the level is really rising or falling. This tolerance is made available to prevent rapid switching between the tables.
RISE is the table number giving the pump speed as a function of the sensed variable when the sensed level is increasing in magnitude. This function includes the definition of the null zone for the pump. A discussion of the pump speed function is presentedin section 8.1.2.2.3.2.
FALL is the table number giving the pump speed as a function of the sensed variable when the sensed level is decreasing in magnitude.
ONPR is the priority to assign to the control point action when the pump speed function requests that the pump be turned on.
OFPR is the priority to assign to the control point action when the pump speed function requests that the pump be turned off.