For an aerator with sudden lateral enlargement and vertical drop in free flow chute,the cavity length is governed by a number of independent parameters, including the Froude number,the ramp height of vertical drop, the ramp angle of vertical drop,and the lateral enlargement width of sidewalls,etc.Based on model experiments,the effects of above-mentioned parameters were observed on the bottom cavity length and the lateral cavity length.The results showed that the bottom cavity length is closely related to the ramp height,the ramp angle,the lateral enlargement width and the Froude number,and with higher ramp height,bigger ramp angle,wider lateral enlargement width,and higher Froude number,the bottom cavity length is longer.Yet the lateral cavity length is mainly connected with the lateral enlargement width and the Froude number,which has little relation to the ramp height and the ramp angle.For the lateral cavity length,it increases with the lateral enlargement width.At the condition of larger size of lateral enlargement,the lateral cavity length increases linearly with the Froude number,while a little decreases when the size of lateral enlargement is smaller.
