Abstract
Experiment on cavitation erosion caused by a cavitating oil jet was performed. The mineral oil type hydraulic fluid with VG 32 was used as the test liquid and the oil temperature was kept at 40℃. The cylindrical specimens with the length of 20 mm, the outer diameter of 20 mm, and the inner diameter of 5, 10, and 15 mm were prepared. The inner diameter of the test chamber was 170 mm, the diameter of the nozzle was 1 mm, the upstream absolute pressure was 10.1 MPa, and the cavitation number defined by the ratio of the downstream pressure to the upstream pressure was 0.02. The stand-off distance was varied from 10 to 25 mm by 2.5 mm. The specimen was eroded partially on the inner wall at a location from the downstream-side end of the specimens. The eroded location was slightly moved to the upstream-side as the stand-off distance became large. The erosion was less observed for specimens with a large inner diameter and for a location with a long stand-off distance.
