,
Full Equations Utilities (FEQUTL) Model for the Approximation
of Hydraulic Characteristics of Open Channels and Control
Structures During Unsteady Flow
LINE 1
Variable: QNTAB
Format: 6X, I5
Example: QNTAB = 1100
Explanation:
|
QNTAB is the cross-section function table number for the cross section used in computing a flow given a friction slope. This flow is used to define the maximum flow for each downstream water-surface elevation to be placed in the 2-D table. The friction slope used for each downstream water-surface elevation is given in the following lines of input. This maximum flow at each downstream water-surface elevation becomes the free flow in the 2-D table of type 14 in FEQ simulation. This free flow must be larger, for the given downtream water-surface elevation, than any flow that will be calculated in the simulation of the unsteady flow through the bridge in FEQ. If the flow is not larger, the maximum flow will be considered as a true free flow in FEQ simulation. This will produce invalid results. |
|
QCTAB is the cross-section function table number for the cross section used in computing a critical-flow value for a given downstream water-surface elevation. An elevation offset may be given later in the input to define the water-surface elevation in the critical-flow section. If the table for QCTAB is zero or blank, a critical flow is not computed in WSPROQZ. If the flow from QNTAB (Line 1) is too large, a water-surface profile through the bridge may not be computed in WSPROQZ because the flow in the bridge opening will be supercritical. If QCTAB is given, the maximum flow is limited to the critical flow estimated from QCTAB. |
|
HDATUM is the elevation of the datum used for computing heads in the 2-D function table. This information is placed in a WSPRO comment and is read in the WSPROT14 command. It is assumed that the flow is zero when the head is zero in FEQ simulation. Therefore, the head datum is the maximum bottom elevation of any cross section in the profile between the exit section and the approach section in the WSPRO description of the bridge. |
|
PFQMIN is the minimum value of partial free-flow fraction to use in defining the partial free flows for the water-surface profiles computed in WSPRO. The value of zero partial free flow is automatically included in WSPROT14. PFQMIN should be smaller than any fraction expected in the unsteady-flow computations in FEQ. |
|
NFRAC is the number of partial free flows to use for a given downstream water-surface elevation in computing the profiles in WSPRO. The partial free flow is given by |
(123)
, LINE 6
Variables: POWER
Format: 6X,F10.0
Example: POWER = 0.5
Explanation:
|
POWER is the power for computing the partial free-flow values in the relation defined previously. If POWER = 1, the partial free flows are uniformly distributed between PFQMIN and 1.0. If POWER is greater than 1, the partial free flows are nonuniformly spaced with the closer spacing being toward PFQMIN. Otherwise, if POWER is less than 1, the partial free flows have closer spacing toward 1.0. A spacing option should be selected that enhances the accuracy of linear interpolation in the table. |
LINE 7
Variables: MAXPRO
Format: 7X,I5
Example: MAXPRO = 200
Explanation:
|
MAXPRO is the maximum number of profiles that can be computed in a single run of WSPRO. Most WSPRO packages are limited to 20 profiles, but versions with extended memory on 486 and Pentium personal computers are available. Input fragments are broken in WSPROQZ computations into blocks that do not exceed this number of profiles for input to WSPRO. However, the breaks must come between downstream water-surface elevations. Each set must complete an integral number of downstream water-surface elevations. For example, if the profile storage limit is 20 and NFRAC is 10, then only two tail-water elevations will be included in each input fragment. For the same limit, a value of 15 for NFRAC would include only one tail-water elevation in the input fragment. In these cases utilizing WSPRO packages with limited profile output, WSPROQZ and WSPRO must be run several times to cover the entire range of upstream and downstream water-surface elevations of interest. The WSPRO output files obtained are then input in sequence on Line 4 of the WSPROT14 command (section 5.22), and the 2-D tables of type 14 are prepared in FEQUTL. |
LINE 8
Variables: LINE
Format: A80
Example: DNSWSE MaxFlow Slope Offset
Explanation:
|
LINE is the heading for the data to follow. |
LINE 9 (Repeated as needed to represent the range of tail-water
elevations to be included in the 2-D table describing bridge
hydraulics determined from WSPRO simulation.)
Variables: DNSWSE, MAXQ, MAXQS, QCOFF
Format: 4F10.0
Example: 1094.6 0.0005
Explanation:
|
DNSWSE is the downstream water-surface elevation. The downstream water-surface elevation must be given on each line of input. Input is terminated by including a line with a value of DNSWSE that is less than the preceding value. MAXQ is the maximum flow rate. MAXQ is a maximum flow rate estimated by the user. If this flow rate is given, it is the maximum flow rate used in the table and the other columns of data are ignored. MAXQS is the friction slope for computation of the maximum flow rate. MAXQS is the friction slope to use with the conveyance found in the cross-section function table referenced by QNTAB (Line 1) to estimate the maximum flow. QCOFF is the elevation offset for calculation of critical flow. If QCTAB (Line 2) is nonzero, the elevation offset is used with DNSWSE to compute a critical flow. If both the critical flow and the friction-slope-based flow are greater than zero, the minimum value of the two flows is retained in WSPROQZ. If only one of these flows is greater than zero, it is retained as the maximum flow in WSPROQZ. |