Changes

[[File:Riser.gif|thumb|A two stage riser with low flow controlled with an orifice and high flow controlled with a weir.]]

[[File:Riser.gif|thumb|500px|A two stage riser with low flow controlled with an orifice and high flow controlled with a weir.]]

There are many configurations for multistage risers according to the flow control requirements.  

There are many configurations for multistage risers according to the flow control requirements.  

C_{w}L_{w}\left ( Z-Z_{0} \right )^{1.5}, & Z_{0}\leq Z\leq Z_{0}+H_{0}\\  

C_{w}L_{w}\left ( Z-Z_{0} \right )^{1.5}, & Z_{0}\leq Z\leq Z_{0}+H_{0}\\  

C_{d}A_{0}\sqrt{2g\left (Z-Z_{0}-0.5H_{0}\right)}, & Z_{0}+H_{0}\leq Z\leq Z_{1}\\  

C_{d}A_{0}\sqrt{2g\left (Z-Z_{0}-0.5H_{0}\right)}, & Z_{0}+H_{0}\leq Z\leq Z_{1}\\  

C_{w}L_{w}\left ( Z-Z_{1} \right )^{1.5}+C_{d}A_{0}\sqrt{2g\left (Z-Z_{1}\right)}, & Z_{1}<Z  

C_{w}L_{w}\left ( Z-Z_{1} \right )^{1.5}+C_{d}A_{o}\sqrt{2g\left (Z-Z_{1}\right)}, & Z_{1}<Z  

\end{matrix}\right.

\end{matrix}\right.

</math>

</math>

*''L_w'' = the length of the weir in m,  

*''L_w'' = the length of the weir in m,  

*''C_d'' = the discharge coefficient of the orifice (often defaulted to 0.6 for a sharp edged orifice),  

*''C_d'' = the discharge coefficient of the orifice (often defaulted to 0.6 for a sharp edged orifice),  

*''A₀'' = the cross-sectional area of the orifice in m²,  

*''A_o'' = the cross-sectional area of the orifice in m²,  

*}}

*}}