AVISO E INFORMACIÓN A LA POBLACIÓN

The Rectangular Weir worksheet dialog box comprises an input section on the left and an output, or results, section on the right.

Additionally, a Messages tab is included in each worksheet. The top section of this tab displays informational calculation messages, while the bottom section lets you enter any explanatory notes that you wish to be associated with the worksheet.

Input:

• Discharge—Volumetric rate of flow, given in units of length (cubed) over time.

• Headwater Elevation—Water elevation upstream of the structure.

• Crest Elevation—Elevation of the bottom of the weir opening.

• Tailwater Elevation—Water elevation downstream of the structure.

• Discharge Coefficient—Discharge coefficient Cd used by FHWA HDS-5 meth-

odology to account for submergence effects and reduce the discharge coefficient that would be obtained without submergence.

• Crest Length—Length of the weir opening measured at the crest, perpendicularly

to the flow direction.

• Number of Contractions—Used when the upstream channel is larger than the

rectangular weir crest length, to account for the contraction of the flow on one or both sides of the weir opening.

Output:

• Headwater Height Above Crest—Water depth upstream of the weir measured

• Tailwater Height Above Crest—Height of the water downstream of the weir

measured from the weir crest (a negative value indicated that the tailwater is below the crest elevation).

• Flow Area—Cross sectional area of flow.

• Velocity—Linear measure of flow rate given in units of length over time. For

weirs, the velocity field is for the velocity of the water through the hydraulic structure

• Wetted Perimeter—Perimeter of flow that travels against a solid boundary. For a

partially full pipe, the wetted perimeter includes all of the flow perimeter except for the top segment, which has a free surface.

• Top Width—Length of the free top surface on the flowing cross section. For a

cross section flowing full, this value is zero.

3.10.2

V-Notch Weir Dialog Box

The V-Notch Weir worksheet dialog box comprises an input section on the left and an output, or results, section on the right.

Additionally, a Messages tab is included in each worksheet. The top section of this tab displays informational calculation messages, while the bottom section lets you enter any explanatory notes that you wish to be associated with the worksheet.

Input:

• Discharge—Volumetric rate of flow, given in units of length (cubed) over time.

• Headwater Elevation—Water elevation upstream of the structure.

• Crest Elevation—Elevation of the bottom of the weir opening.

• Tailwater Elevation—Water elevation downstream of the structure.

• V-Notch Weir Coefficient—Coefficients for V-notched weirs vary with the angle

of the notch and with head depth. See “V-Notch Weir Coefficient of Discharge” on page 5-157.

• Notch Angle—Angle of the V-Notch weir opening measured from one side to the

other side. Output:

• Headwater Height Above Crest—Water depth upstream of the weir measured

from the crest of the weir.

• Tailwater Height Above Crest—Height of the water downstream of the weir

measured from the weir crest (a negative value indicated that the tailwater is below the crest elevation).

• Flow Area—Cross sectional area of flow.

• Velocity—Linear measure of flow rate given in units of length over time. For

weirs, the velocity field is for the velocity of the water through the hydraulic structure

• Wetted Perimeter—Perimeter of flow that travels against a solid boundary. For a

partially full pipe, the wetted perimeter includes all of the flow perimeter except for the top segment, which has a free surface.

• Top Width—Length of the free top surface on the flowing cross section. For a

cross section flowing full, this value is zero.

3.10.3

Cipoletti Weir Dialog Box

The Cipoletti Weir worksheet dialog box comprises an input section on the left and an output, or results, section on the right.

Additionally, a Messages tab is included in each worksheet. The top section of this tab displays informational calculation messages, while the bottom section lets you enter any explanatory notes that you wish to be associated with the worksheet.

Input:

• Discharge—Volumetric rate of flow, given in units of length (cubed) over time.

• Headwater Elevation—Water elevation upstream of the structure.

• Crest Elevation—Elevation of the bottom of the weir opening.

• Tailwater Elevation—Water elevation downstream of the structure.

• Discharge Coefficient—Weir coefficient obtained from experimental data,

dependent on the shape of the weir.

• Crest Length—Length of the weir opening measured at the crest, perpendicularly

to the flow direction. Output:

• Headwater Height Above Crest—Water depth upstream of the weir measured

from the crest of the weir.

• Tailwater Height Above Crest—Height of the water downstream of the weir

measured from the weir crest (a negative value indicated that the tailwater is below the crest elevation).

• Equal Side Slopes—Slope of trapezoidal channel, assumed to be identical on

both sides.

• Velocity—Linear measure of flow rate given in units of length over time. For

weirs, the velocity field is for the velocity of the water through the hydraulic structure

• Wetted Perimeter—Perimeter of flow that travels against a solid boundary. For a

partially full pipe, the wetted perimeter includes all of the flow perimeter except for the top segment, which has a free surface.

• Top Width—Length of the free top surface on the flowing cross section. For a

cross section flowing full, this value is zero.

3.10.4

Broad Crested Weir Dialog Box

The Broad Crested Weir worksheet dialog box comprises an input section on the left and an output, or results, section on the right.

Additionally, a Messages tab is included in each worksheet. The top section of this tab displays informational calculation messages, while the bottom section lets you enter any explanatory notes that you wish to be associated with the worksheet.

Input:

• Discharge—Volumetric rate of flow, given in units of length (cubed) over time.

• Headwater Elevation—Water elevation upstream of the structure.

• Crest Elevation—Elevation of the bottom of the weir opening.

• Tailwater Elevation—Water elevation downstream of the structure.

• Crest Surface Type—Surface of a broad crested weir, defined as Paved or

Gravel. Used by FHWA HDS-5 methodology for calculating the discharge coeffi- cient and submergence factor.

• Crest Breadth—Width (Lr) of the weir, measured in the direction of flow.

• Crest Length—Length of the weir opening measured at the crest, perpendicularly

to the flow direction. Output:

• Headwater Height Above Crest—Water depth upstream of the weir measured

from the crest of the weir.

• Tailwater Height Above Crest—Height of the water downstream of the weir

measured from the weir crest (a negative value indicated that the tailwater is below the crest elevation).

• Discharge Coefficient—Weir coefficient obtained from experimental data,

• Submergence Factor—Ratio (kt) used by FHWA HDS-5 methodology for calcu-

lating the submergence effect and reduce the discharge coefficient.

• Adjusted Discharge Coefficient—Discharge coefficient (Cd) used by FHWA

HDS-5 methodology to account for submergence effects and reduce the discharge coefficient that would be obtained without submergence.

• Flow Area—Cross sectional area of flow.

• Velocity—Linear measure of flow rate given in units of length over time. For

weirs, the velocity field is for the velocity of the water through the hydraulic structure

• Wetted Perimeter—Perimeter of flow that travels against a solid boundary. For a

partially full pipe, the wetted perimeter includes all of the flow perimeter except for the top segment, which has a free surface.

• Top Width—Length of the free top surface on the flowing cross section. For a

cross section flowing full, this value is zero.

3.10.5

Generic Weir Dialog Box

The Generic Weir worksheet dialog box comprises an input section on the left and an output, or results, section on the right.

Additionally, a Messages tab is included in each worksheet. The top section of this tab displays informational calculation messages, while the bottom section lets you enter any explanatory notes that you wish to be associated with the worksheet.

Input:

• Discharge—Volumetric rate of flow, given in units of length (cubed) over time.

• Headwater Elevation—Water elevation upstream of the structure.

• Crest Elevation—Elevation of the bottom of the weir opening.

• Discharge Coefficient Weir—Coefficient C used in the general weir equation.

• Crest Length—Length of the weir opening measured at the crest, perpendicularly

to the flow direction. Output:

• Headwater Height Above Crest—Water depth upstream of the weir measured

from the crest of the weir.

• Flow Area—Cross sectional area of flow.

• Velocity—Linear measure of flow rate given in units of length over time. For

weirs, the velocity field is for the velocity of the water through the hydraulic structure

• Wetted Perimeter—Perimeter of flow that travels against a solid boundary. For a

partially full pipe, the wetted perimeter includes all of the flow perimeter except for the top segment, which has a free surface.

• Top Width—Length of the free top surface on the flowing cross section. For a

cross section flowing full, this value is zero.

3.11

Orifice Worksheet Dialog Boxes

The available orifice worksheets are as follows: • “Rectangular Orifice Dialog Box”

• “Circular Orifice Dialog Box”

• “Generic Orifice Dialog Box”