CAVITATION STUDY OF A PROPELLER OPERATING IN A NONUNIFORM FLOW CREATED BY A WIRE GRID SCREEN

摘要

Tunnel test results are presented for nonuniform flow cavitation studies of a 4-bladed ITTC design subcavitating propeller. The nonuniform flows were generated by wire mesh screens located upstream from the propeller. The first objective of the tests was to compare the cavitation of the propeller operating in a given axial wake as produced by a wire mesh with the cavitation in the same wake as reported by van Manen in the 10th ITTC proceedings. The second objective was to determine the effect on the propeller cavitation of modifying the axial inflow velocity so as to obtain the same local inflow angles as produced by both the axial and tangential wake of the ship.nDifferences were observed in the cavitation patterns produced by the wakes with and without tangential component correction, but the expected transverse asymmetry was not consistently observed. The cavitation patterns in the uncorrected wake agreed well with those observed by van Manen except that the intensity varied suggesting that the cavitation index used in the two studies may not be equivalent.