Inlet Manifold Equations
\large
$$
\Delta H_
= {{\left( {V_
- V_
} \right)V_
} \over g}
$$
$$
\sum\limits_
^
{\Delta H_
= V_M ^2 } \over g}{{n - 1} \over {2n
\to {\rm{Approaches}}\;} V_M ^2 } \over g}\;{\rm{for
\;{\rm{large}}\;{\rm{n}}
$$
$$
{\rm{where }}V_M = {\rm{velocity}}\;{\rm{in}}\;{\rm{the}}\;{\rm{manifold}}
$$
$$
V_
\;{\rm{and}}\;V_
\;{\rm{are}}\;{\rm{the}}\;{\rm{velocities}}\;{\rm{before}}\;{\rm{and}}\;{\rm{after}}\;{\rm{the}}\;{\rm{expansion}}
$$
$$
f = 0.25} \over {\left[ {\log \left( {{\varepsilon \over {3.7D
+ {{5.74} \over {{\mathop
\nolimits} ^
}}} \right)} \right]^2 }}
$$
$$
C_
= \left[ {f{{L_M } \over {D_M }}2n - 1} \over {6n
+ n - 1} \over n
\right]
$$
$$
K_
= K_
\left( {{
\over {nK_
D_P^2 }}} \right)^2
$$
$$
\Pi Q = \sqrt {{{C{p_
} + K_
} \over {C_{p_
} + K_
}}}
$$
$$
D_M = \left( {{
\over {g\pi ^2 h_l }}{{C_
} \over
}} \right)
$$
Energy Dissipation Constraint on Port Velocity
\large
$$
D_
\cong \left[ {{1 \over {20\varepsilon _
}}\left( {{{4Q_
} \over {\pi K_
}}} \right)3 } \right]1 \over 7
$$
$$
V_
= {{4Q_
^1 \over 7
} \over {\pi \left[ {{1 \over {20\varepsilon _
}}\left( {{4 \over {\pi K_
}}} \right)3 } \right]2 \over 7
}}
$$
Scour velocity
Design manifolds to have a flow velocity not less than 0.15 m/s nor greater than 0.45 m/s.
The minimum scour velocity is:
\large
$$
\tau {o
} =
d_
\left( {\rho _
- \rho _
} \right)g\tan \theta
$$
$$
V_
= \sqrt {{{\tau {o
} } \over {\rho _
}}{{\sqrt
} \over
}}
$$
$$
\varepsilon _
= {1 \over {20D_
}}\left( {{{V_
} \over {K_
}}} \right)^3
$$