Spreadsheet: 134585d1325495195-excel-2007-page-setup-trial-print
Sheet: stilling basin

Reference |  |  |  | Calculation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Output
 |  |  |  |  | Hydraulic design of Stilling basin
 |  |  |  |  | Consider the downstream end of conduit.
 |  |  |  |  | Velocity of flow (v) |  |  |  |  |  |  |  |  | = | 43.84 |  | ft/s  ( =v1)
 |  |  |  |  | Depth of flow (d) |  |  |  |  |  |  |  |  | = | 6.16 |  | ft | ( =d1)
 |  |  |  |  | Invert elevation of Conduit |  |  |  |  |  |  |  |  | = | 30 |  | ft | ( =Z1)
 |  |  |  |  | Elevation of water surface |  |  |  |  |  |  |  |  | = |  |  | + |  |  | = |  |  | ft
 |  |  |  |  | Computation of parameters tof ail water
 |  |  |  |  | The flow that coming through the conduit, then entered to the Stilling
 |  |  |  |  | basin and after that connected to the existing stream.
 |  |  |  |  | Select, the section of flow just before to the existing stream with
 |  |  |  |  | Required maximum discharge (Q) |  |  |  |  |  |  |  |  |  |  |  | = | 2525 |  | cusec
Site survey |  |  |  |  | Existing stream bed level |  |  |  |  |  |  |  |  |  |  |  | = | 21.33 |  | ft | ( =Z4)
plan |  |  |  |  | Existing stream bed gradient (s) |  |  |  |  |  |  |  |  |  |  |  | = | 0.001
 |  |  |  |  | Side slope |  |  |  |  |  |  |  |  |  |  |  | = | 1 : 1
 |  |  |  |  | [NAME] of the canal |  |  |  |  |  |  |  |  |  |  |  | = | x  ft
 |  |  |  |  | Take, depth of flow |  |  |  |  |  |  |  |  |  |  |  | = | [NAME]
 |  |  |  |  |  |  |  |  |  |  | y ft |  |  |  |  |  |  |  |  | (√2) y |  | ft
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | ft
 |  |  |  |  |  |  |  |  |  |  |  | x | ft
 |  |  |  |  | Considering a point of flow just before to the existing stream with the
 |  |  |  |  | velocity v,
Eq. 30 |  |  |  |  | v | = | 1.486 |  | r2/3s1/2
DSD, 3rd edt. |  |  |  |  |  |  | n
Para. B-2( c) |  |  |  |  | For straight and uniform earth channels,
Appendix B |  |  |  |  | [NAME] coefficient (n) |  |  |  |  |  |  |  |  |  |  | = | 0.025
DSD, 3rd edt. |  |  |  |  | v | = | 1.486 |  | x |  | r 2/3 x |  |  | 1/2
 |  |  |  |  | v | = |  |  | r 2/3
Para. B-2 (c ) |  |  |  |  | Hydraulic radius ( r) |  |  |  |  |  |  | = | a
Appendix B |  |  |  |  |  |  |  |  |  |  |  |  | p
DSD-USBR
 |  |  |  |  | Area of the flow, a = |  |  |  |  |  |  | [x + (x+2y)] y |  |  |  |  | = | ( x + y ) y
 |  |  |  |  |  |  |  |  |  |  |  |  |  | 2
APPAREKKA ARA PROJECT |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Feature |  |  |  | Hydraulic  Design of Stilling Basin
PLANNING & DESIGN  UNIT (SOUTHERN) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Designed |  |  |  |  |  |  |  |  |  | Date
IRRIGATION DEPARTMENT |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Checked |  |  |  |  |  |  |  |  |  | Date
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Page
Reference |  |  |  | Calculation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Output
 |  |  |  |  | Wetted perimeter (p) |  |  |  |  |  |  | = |  | + | (√2) y |  | + | (√2) y |  |  | = | x + 2√2 y
Para. B-2 (c ) |  |  |  |  | Hydraulic radius ( r) |  |  |  |  |  |  | = | a |  | =
Appendix B |  |  |  |  |  |  |  |  |  |  |  |  | p
DSD-USBR
 |  |  |  |  | Equation 1 and 3,
 |  |  |  |  | v | = |  |  |  |  |  |  |  | 2/3
 |  |  |  |  | Maximum dischage that allow to flow through above stream section, Q
 |  |  |  |  | Q | = | a.v
 |  |  |  |  | From Equation 2 and 4,
 |  |  |  |  |  |  | = |  |  |  |  | x |  |  |  |  |  |  |  | 2/3
 |  |  |  |  |  |  |  | = | [ |  |  |  |  | ] 5/3
 |  |  |  |  |  |  |  |  | [ |  |  |  |  | ] 2/3
 |  |  |  |  | Then substituting the values for x and y to satisfy the equation 5. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | x  = | 59.72
 |  |  |  |  | Also, value of v (from equation 4) should be less than 6.0 ft/s. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | y  = | 6.5
 |  |  |  |  | Because, maximum velocity of flow in excavated earth canal is 6.0 ft/s.
 |  |  |  |  | x | = | 59.72 |  | ft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (x + y)y =
 |  |  |  |  | y | = | 6.5 |  | ft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | [(x + y)y]5/3 =
 |  |  |  |  | Equation 2, |  |  |  | a | = |  |  |  | ft2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | x + 2√2 y =
 |  |  |  |  | Equation 4, |  |  |  | v | = |  |  | ft/s |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | [x + 2√2 y]2/3 =
 |  |  |  |  |  |  |  |  | Q | = | a . v |  | = |  |  |  | x |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Ans =
 |  |  |  |  |  |  |  |  |  | = |  |  |  | cusec |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Target value =
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | v =
 |  |  |  |  | Finally, following parameters are selected.
 |  |  |  |  | [NAME] of the canal |  |  |  |  |  |  |  |  |  |  |  | = | 59.7 |  | ft
 |  |  |  |  | Depth of flow |  |  |  |  |  |  |  |  |  |  |  | = | 6.5 |  | ft | ( =d4)
 |  |  |  |  | Velocity of flow, v |  |  |  |  |  |  |  |  |  |  |  | = | 5.87 |  | ft/s | ( =v4)
 |  |  |  |  | Maximum dischage in stream section |  |  |  |  |  |  |  |  |  |  |  | = | 2526.62 |  |  | cusec
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | ≈ | 2525 |  | cusec
APPAREKKA ARA PROJECT |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Feature |  |  |  | Hydraulic  Design of Stilling Basin
PLANNING & DESIGN  UNIT (SOUTHERN) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Designed |  |  |  |  |  |  |  |  |  | Date
IRRIGATION DEPARTMENT |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Checked |  |  |  |  |  |  |  |  |  | Date
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Page
Reference |  |  |  | Calculation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Output
 |  |  |  |  | Section 1 indicates the downstream end of conduit.
Para.9.19.(b) |  |  |  |  | [NAME] number (F) of flow at section 4 |  |  |  |  |  |  |  |  |  |  |  | = | v
DSD, 3rd edt. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (gd)1/2
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | =
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | ( | 32.2  x |  |  |  | )1/2
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | = |  |  | < | 1
 |  |  |  |  | Hence flow is sub critical.
 |  |  |  |  | Elevation of water surface at the point just before to the existing stream
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | = |  |  | +
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | = |  |  | ft
 |  |  |  |  | Elevation of water surface at downstream end of conduit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | = |  |  | ft
 |  |  |  |  | Hence Conduit isn't submerged by the down stream flow.
 |  |  |  |  | Assume, width of stilling basin |  |  |  |  |  |  |  |  |  |  |  |  |  | = | 15 |  | ft
 |  |  |  |  | Discharge per unit width (q) of stilling basin |  |  |  |  |  |  |  |  |  |  |  |  |  | =
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | = |  |  |  | cusec/ft
Para. 9.25(a) |  |  |  |  | Critical depth of flow (dc) |  |  |  |  |  |  |  |  |  |  |  |  |  | = | ( q2/g )1/3
DSD, 3rd edt. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | = |  |  | 2 | 1/3
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 32.2
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | = |  |  | ft
Eq. 32 |  |  |  |  | Apply Energy equation for location 1 & 4,
Appendix B |  |  |  |  | Z1 | + | d1 | + | hv1 |  | = | Z4 | + | d4 | + | hv4 | + | hL
DSD, 3rd edt. |  |  |  |  | hL |  | = | Z1 | + | d1 | + | hv1 | - | Z4 | - | d4 | - | hv4
 |  |  |  |  |  |  | = | Z1 | + | d1 | + | v12 | - | Z4 | - | d4 | - | v42
 |  |  |  |  |  |  |  |  |  |  |  | 2g |  |  |  |  |  | 2g
 |  |  |  |  |  |  | = |  |  | + |  |  | + |  |  | 2 | - |  |  | - |  |  | - |  |  | 2
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 x 32.2 |  |  |  |  |  |  |  |  |  | 2 x 32.2
 |  |  |  |  | hL |  | = |  |  |  | ft
 |  |  |  |  | hL |  | = |  |  |  | = |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | d2/d1 | = | 8.89
 |  |  |  |  | dc |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (d2/d1)-1 | =
Eq. 9.4 |  |  |  |  | hL |  | = | [( d3/d2) - 1]3 |  |  |  |  | 2 |  |  |  |  |  |  | 1/3 |  |  |  |  |  |  |  |  |  |  |  | [(d2/d1)-1]^3 | =
Hydraulic |  |  |  |  | dc |  |  | 4(d3/d2) |  |  |  |  | ( d3/d2) x [ ( d3/d2) + 1] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | [(d2/d1)-1]^3 | =
Energy |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4(d2/d1)
Dissipators |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (d2/d1)[(d2/d1)+1] | =
by [NAME] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 | =
[NAME] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (d2/d1)[(d2/d1)+1]
(HED)
APPAREKKA ARA PROJECT |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Feature |  |  |  | Hydraulic  Design of Stilling Basin
PLANNING & DESIGN  UNIT (SOUTHERN) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Designed |  |  |  |  |  |  |  |  |  | Date
IRRIGATION DEPARTMENT |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Checked |  |  |  |  |  |  |  |  |  | Date
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Page