online_vee_notch1:   Calculation of discharge through a fully contracted V-notch weir

V-notch weir
Formula:


Q = 4.28 Ce tan (θ/2) (H + k)5/2          [in U.S. Units]


Head H on the weir, in m [or ft]
Width B of the channel, in m [or ft]
Side width b, in m [or ft]
Angle θ  in radians
Ce and k are function only of θ
(in degrees)

Discharge Q  in L/s [or cfs]

For a fully contracted V-notch weir:  H/B ≤ 0.2
Partially contracted 90° V-notch weir calculator
See USBR Manual for general methodology



INPUT DATA:       [Description]

Select Units:     

Head H :     
  
Warning: Undefined variable $headunits in /var/www/html/ponce/onlineveenotch1.php on line 202
[ H > 0 ]
Width B :     
  
Warning: Undefined variable $headunits in /var/www/html/ponce/onlineveenotch1.php on line 208
[ B > 0 ]
Width b :     
  
Warning: Undefined variable $headunits in /var/www/html/ponce/onlineveenotch1.php on line 214
[ b > 0 ]
Angle θ (degrees) :     
 
[ θ > 0 ]


OUTPUT:

Warning: Undefined variable $ratiobtoh in /var/www/html/ponce/onlineveenotch1.php on line 227

Warning: Undefined variable $ratiobtoh in /var/www/html/ponce/onlineveenotch1.php on line 229

Deprecated: round(): Passing null to parameter #1 ($num) of type int|float is deprecated in /var/www/html/ponce/onlineveenotch1.php on line 229

Warning:  Ratio b/H = 0 < 2.

Warning: Undefined variable $ratiohtob in /var/www/html/ponce/onlineveenotch1.php on line 233

Warning: Undefined variable $ratiohtob in /var/www/html/ponce/onlineveenotch1.php on line 238

Warning: Undefined variable $ratiohtob in /var/www/html/ponce/onlineveenotch1.php on line 244

Deprecated: round(): Passing null to parameter #1 ($num) of type int|float is deprecated in /var/www/html/ponce/onlineveenotch1.php on line 244

Ratio H/B = 0 ≤ 0.2.  Weir is fully contracted.

Discharge  Q :  
Warning: Undefined variable $discharge in /var/www/html/ponce/onlineveenotch1.php on line 251

Deprecated: round(): Passing null to parameter #1 ($num) of type int|float is deprecated in /var/www/html/ponce/onlineveenotch1.php on line 251
0  
Warning: Undefined variable $dischargeunits in /var/www/html/ponce/onlineveenotch1.php on line 251



            

  Your request was processed at  10:57:18 pm on April 3rd, 2025   [ 250403  22:57:18 ].


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