Unsteady Cavitation on an Oscillating Hydrofoil.

摘要

Bent trailing edges and erosion, which are often observed on marine propellers, are attributed mainly to unsteady cavitation caused by the nonuniformity of flow field behind ship's hull. In order to improve the physical understanding, the formation of cloud cavitation and bubble collapse on marine propellers, a two-dimensional hydrofoil was tested at the DTNSRDC 36-inch water tunnel under pitching oscillation. The inception of cavitation, cavity growth and collapse were investigated in terms of the reduced frequency. The possible cause of 'cloud cavitation' and the applicability of a quasi-steady method to predict unsteady cavitation were investigated and discussed. (Author)