Hydrodynamic calculation vertical lift gates
Values for calculation
Calculation
Cross-sectional area of the conduit
Area of the horizontal projection of the top seal
Minimum cross-sectional area between upstream face of the gate and upstream wall of the gate chamber
Cross-sectional area of the contracted jet issuing from the gap between the downstream face of the gate and the downstream wall of the gate chamber
Coefficient $ K_T $
Velocity before the gate
Theoretical pressure in the gate at full opening
Effective closing time factor
Under-pressure behind the gate
Pressure parameter
Gate position |
Flow coefficient |
Coefficient $ K_B $ |
Coefficient of contraction |
Gate opening |
---|---|---|---|---|
$ s/s_0 $ | $ K_Q $ | $ K_B $ | $ C_c $ | $ s $ |
$ \mathrm{\ } $ | $ \mathrm{\ } $ | $ \mathrm{\ } $ | $ \mathrm{\ } $ | $ \mathrm{mm} $ |
No data |
No data |
No data |
No data |
No data |
Gate position |
Loss coefficient |
Reduced free flow area in the throttle control system |
Relative flow |
Flow of water before the gate |
Water velocity before the gate |
Velocity in the contracted jet issuing from underneath the gate |
---|---|---|---|---|---|---|
$ s/s_0 $ | $ ζ $ | $ f_r $ | $ Q_p $ | $ Q $ | $ v $ | $ v_j $ |
$ \mathrm{\ } $ | $ \mathrm{\ } $ | $ \mathrm{\ } $ | $ \mathrm{\ } $ | $ \mathrm{m^3/s} $ | $ \mathrm{m/s} $ | $ \mathrm{m/s} $ |
No data |
No data |
$ Q_p\ [-] $
No data |
No data |
No data |
No data |
Gate position |
Loss of pressure on the gate |
Pressure on the gate |
Cavitation number |
Force on gate |
---|---|---|---|---|
$ s/s_0 $ | $ H_L $ | $ H_v $ | $ σ $ | $ W $ |
$ \mathrm{\ } $ | $ \mathrm{m} $ | $ \mathrm{m} $ | $ \mathrm{\ } $ | $ \mathrm{kN} $ |
No data |
$ H_v\ [\mathrm{m}] $
No data |
No data |
No data |
Gate position |
Downpull resulting from the difference between the pressures acting on the top and bottom surfaces of the gate |
Downpull resulting from the pressure differential acting on the horizontal protrusions of the gate |
Downpull resulting from the lip |
Downpull force |
---|---|---|---|---|
$ s/s_0 $ | $ P_1 $ | $ P_2 $ | $ P_3 $ | $ P $ |
$ \mathrm{\ } $ | $ \mathrm{kN} $ | $ \mathrm{kN} $ | $ \mathrm{kN} $ | $ \mathrm{kN} $ |
No data |
No data |
No data |
No data |
No data |
Gate position |
Depth of water at vena contracta |
Froude number |
Aerated coefficient |
---|---|---|---|
$ s/s_0 $ | $ h_c $ | $ F_c $ | $ β $ |
$ \mathrm{\ } $ | $ \mathrm{m} $ | $ \mathrm{\ } $ | $ \mathrm{\ } $ |
No data |
No data |
No data |
No data |
Gate position |
Coefficient of under-pressure of aerated hole |
Under-pressure in the aerated pipeline |
Air flow |
Air velocity |
The flow area of the aerated hole |
The flow area of the aerated pipeline |
---|---|---|---|---|---|---|
$ s/s_0 $ | $ f_{air} $ | $ p_{air} $ | $ Q_{air} $ | $ v_{air} $ | $ A_{air} $ | $ A_{air-pipe} $ |
$ \mathrm{\ } $ | $ \mathrm{\ } $ | $ \mathrm{Pa} $ | $ \mathrm{m^3/s} $ | $ \mathrm{m/s} $ | $ \mathrm{m^2} $ | $ \mathrm{m^2} $ |
No data |
No data |
No data |
No data |
No data |
No data |
No data |