Keynote Speaker of the 19th congress of IAHR-APD Keynote Speaker IV Weilin XU, Sichuan University, CHINA Title of the Speech STUDY ON AERATION FOR AVOIDING CAVITATION DAMAGE IN HYDRAULIC ENGINEERING Personal Profile Prof. Weilin Xu, the Director of The State Key Laboratory of Hydraulics and Mountain River Engineering, finished his PhD Study in 1991 at former Chengdu University of Science and Technology which has joined with Sichuan University Since 1994. Prof Xu mainly concentrated on the study of Hydraulics, especially on the micro-mechanism of high speed flow and the new safety techniques on the high speed flow from the high dam spillways. He has made some original and initiative studies in cavitation and aeration including self-aeration of the high speed flows for avoiding cavitation damages to the hydraulic structures. In the aspect of new techniques for high speed spillway flow, he invented no-collision discharging technique from both side orifices from high arch-dam sluices and submerged horizontal jetflows from gravity dams, and etc. In addition, his has studied quantitatively the increasing mechanism of dam-breaking flooding flows from cascade hydraulic projects. He has also proposed new simulation methods on the turbulent high speed flow from the spillway of high dams. His theoretical achievements have published in Journal of Hydraulic Engineering, Journal of Hydraulic Research and etc. Results of his study have successfully adopted by many worldwide known high dam projects in China. Abstract: Cavitation damage is common in the high dam hydropower engineering. The alleviating measures for cavitation damage mainly include shape optimization, surface smoothness control, usingcavitation resistant material, and aeration. Among them, aeration is proved by practice as an efficient mitigation cavitationmeasure. The State Key Laboratory of Hydraulics and Mountain River Engineering(Sichuan University,China)conducted the massivetheoretical and technical research about aeration mitigation cavitation. In this paper, the mechanism of aeration mitigation cavitationwas further revealed by adopting high speed video technology,and some new technologies of aeration mitigation cavitation for different type of spillway tunnelwere presented. Besides, this paper also studied the aeration mitigation cavitationissue in stepped spillway, and analyzed the critical condition of cavitation damage in orifice tunnel. Parts of results mentioned above have been applied into someconstructed and constructing large water conservancy and hydropower project.