Design of V notch for discharge measurement

 

 

Installation Guidelines for V notch

 

 

 

 

• Use a 2mm Thick Mild Steel plate to make the V notch. Make a 90^o V

• Water surface downstream of the weir should be at least 6 cm below the bottom of the V to allow a free flowing waterfall.

• The bottom of the "V" only needs to be 10 cm (=P) above the bottom of the upstream channel,
• the approach channel (=B) only needs to be 2 ft. wide,

• Head (h) should be measured at a distance of at least 4h upstream of the weir.

 

Q = 4.28 C tan(θ/2)( h+k)^5/2

 

where

Q = flow rate (cfs)

C= Discharge Coefficient, C=0.578 for 90^o V notch

θ = v-notch angle ( 90^o

h = head on the weir (ft)

k = Head Correction factor(Ft)

• k (ft.) = 0.0144902648 - 0.00033955535 Ø + 3.29819003x10^-6 ز - 1.06215442x10^-8 س
  where Ø is the V notch angle in degrees ( 90^o

 

 

Source: ENVO PROJECTS. NEW DELHI-25 9899300371, 9810004529

Saleem Asraf Syed Imdaadullah
Mobile : 9899300371
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