online_vee_notch1:   Calculation of discharge through a fully contracted 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:      SI (metric) U.S. Customary Head H :         [ H > 0 ] Width B :         [ B > 0 ] Width b :         [ b > 0 ] Angle θ (degrees) :        [ θ > 0 ] OUTPUT: Warning:  Ratio b/H = 0 < 2. Ratio H/B = 0 ≤ 0.2.  Weir is fully contracted. Discharge  Q :   0     Your request was processed at  11:00:37 pm on October 30th, 2025   [ 251030  23:00:37 ]. Thank you for running   online_vee_notch1   Please call again.   [131111]