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Inlet
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Manifold Equations
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(eq-1) Equations !Inlet manifold.PNG! {latex} \large $$ \Delta H_{\exp ansion} = {{\left( {V_{in} - V_{out} } \right)V_{out} } \over g} $$ {latex} {latex} \large $$ \sum\limits_{i = 1}^{n - 1} {\Delta H_{\exp ansion} = {{V_M ^2 } \over g}{{n - 1} \over {2n}} \to {\rm{Approaches}}\;} {{V_M ^2 } \over g}\;{\rm{for}}\;{\rm{large}}\;{\rm{n}} $$ $$ {\rm{where }}V_M = {\rm{velocity}}\;{\rm{in}}\;{\rm{the}}\;{\rm{manifold}} $$ $$ V_{in} \;{\rm{and}}\;V_{out} \;{\rm{are}}\;{\rm{the}}\;{\rm{velocities}}\;{\rm{before}}\;{\rm{and}}\;{\rm{after}}\;{\rm{the}}\;{\rm{expansion}} $$ $$ f = {{0.25} \over {\left[ {\log \left( {{\varepsilon \over {3.7D}} + {{5.74} \over {{\mathop{\rm Re}\nolimits} ^{0.9} }}} \right)} \right]^2 }} $$ $$ C_{long} = \left[ {f{{L_M } \over {D_M }}{{2n - 1} \over {6n}} + {{n - 1} \over n}} \right] $$ $$ K_{control} = K_{e_P } \left( {{{D_M^2 } \over {nK_{vc} D_P^2 }}} \right)^2 $$ $$ \Pi _Q = \sqrt {{{C_{p_{short} } + K_{control} } \over {C_{p_{long} } + K_{control} }}} $$ $$ D_M = \left( {{{8Q_M ^2 } \over {g\pi ^2 h_l }}{{C_{long} } \over {1 - \Pi _Q^2 }}} \right) $$ |
Energy Dissipation Constraint on Port Velocity
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(eq-2) \large $$ D_{Port} \cong \left[ {{1 \over {20\varepsilon _{Max} }}\left( {{{4Q_{Port} } \over {\pi K_{vc} }}} \right)^3 } \right]^{{1 \over 7}} $$ $$ V_{Port} = {{4Q_{Port} ^{{1 \over 7}} } \over {\pi \left[ {{1 \over {20\varepsilon _{Max} }}\left( {{4 \over {\pi K_{vc} }}} \right)^3 } \right]^{{2 \over 7}} }} $$ |
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:
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\large $$ \tau _{o_{Min} } = {2 \over 3}d_{Floc} \left( {\rho _{Floc} - \rho _{H2O} } \right)g\tan \theta $$ $$ V_{Scour} = \sqrt {{{\tau _{o_{Min} } } \over {\rho _{H_2 O} }}{{\sqrt {500000} } \over {0.332}}} $$ (eq-3) $$ \varepsilon _{Max} = {1 \over {20D_{Port} }}\left( {{{V_{Scour} } \over {K_{vc} }}} \right)^3 $$ |