Effect of upstream aerator in ogee section of spillway tunnel on cavitation alleviation of downstream sidewall

Based on an analysis of causes of cavitation damages to the downstream at the end of ogee section in the spillway tunnel of open channel,it is pointed out that the aeration measure for sidewall protection nearby the downstream of ogee section should be paid much attention in aerator design.Large-scale model tests were performed to study whether the cavitation alleviation of downstream sidewall in ogee section can be realized by enhancement of the aeration capacity of upstream aerator.The results show that the enhancement of the aeration capacity of upstream aerator can improve the effect of aeration on downstream sidewall to a certain degree and reduce the clean water region of the sidewall;but it cannot eliminate the clean water region completely.Therefore,it is difficult to control cavitation of downstream sidewall thoroughly only by this measure.