Serialgradesofcementmortarspecimenshavebeentestedonthemodelofcon-crete-liningflooddischargetunnelwithorifice,Theresultsshowthatincipientcavitationerosionnumberismuchsmallerthanincipientcavitationnumber.Basedontheprincipleofbubbledy-namics,theflowspeedeffectonincipientcavitationerosionnumberforcementmortarispre-sented.