Damage due to the coupled action of silts abrasion and cavitation erosion was experimentally studied using water channel in which artificial silt (Al2O3) were included. It was confirmed that the incipient cavitation number in silt laden water increased by 10-15% compared with that in tap water. It was shown that the magnitude of impact pressure measured by the pressure detecting films and casing vibration-acceleration had good correlation with the cavitation erosion intensity but not with the abrasive wear intensity. The damage patterns on aluminum specimens were greatly affected by the cavitation occurrence, but the amount of damaged volume was almost constant with and without cavitation. A ploughing type of abrasive wear was mainly observed on the damaged surface by scanning electron microscope.
