Influences of ramp size,Froude number and bottom cavity pressure on the cavity backwater of an aerator

Aerator is an important device to protect high-speed flow release works from cavitation damage. For a bottom aerator of effective air entrainment,serious backwater in the bottom cavity should be avoided,but the factors that affect the backwater are usually complex. This paper analyzes the effects of the height and deflect angel of the ramp,the flow Froude number and the negative cavity pressure,through calculations by using the equations of jet trajectory and backwater established by the authors. This analysis shows that a ramp of greater height or greater deflect angle within a certain range is favorable to backwater control. An increase in Froude number causes a smaller backwater volume,while a lower negative cavity pressure causes a larger volume. These results can be referenced in aerator design.