Mixed / chevron baffles fishway
Excerpt from Larinier, 20021
Hydraulic laws given by abacuses
Experiments conducted by Larinier, 20021 allowed to establish abacuses that link adimensional flow \(q^*\) :
to upstream head \(ha\) and the average water level in the pass \(h\) :
Abacuses of a mixed / chevron baffles fishway for a slope of 10% (Excerpt from Larinier, 20021)
Abacuses of a mixed / chevron baffles fishway for a slope of 15% (Excerpt from Larinier, 20021)
To run calculations for all slopes between 8% and 22%, polynomes coefficients of abacuses above are themelves adjusted in the form of slope \(S\) depending polynomes.
We thus have:
Calculation of \(ha\), \(h\) and \(Q\)
We can then use those coefficients to calculate \(ha\), \(h\) and \(q^*\):
Using the positive inverse function, depending on \(ha/L\), we get:
And we finally have:
Calculation limitations of \(q^*\), \(ha/a\) and \(h/a\) are determined based on the extremities of the abacuses curves.
Flow velocity \(V\) corresponds to the minimum flow speed given the flow section \(A_w\) at the perpendicular of the baffle :
for mixed / chevron baffles fishways using the notation of the schema above, we have: