Study on Hydraulic Characteristic of Aerator with Side-walls Sudden Enlargement in Free-Flow Spillway Tunnel

摘要

Engineering practices showed side-walls in free-flow discharge tunnels with high speed flows and low pressure tended to be damaged by cavitation, especially behind concave reach. In this paper through experiment an aerator with side-walls sudden enlargement and soleplate vertical dropping was introduced on the concave reach bottom of the Vertical-Bend free-flow spillway tunnel side-walls. By applying this type of aerator, air entrainment increases significantly and un-airflow areas disappear. Experimental observations show that lateral cavity and bottom cavity are linked to each other and the forced aeration forms behind the aerator, which protects sidewalls and soleplates against cavitation damage.