Propeller cavitation: Further tests on 16in. propeller models in the King’s College cavitation tunnel 1

Results are presented for a four-bladed .60 expanded-area ratio merchant-ship propeller series tested in the cavitation tunnel in the Department of Naval Architecture and Shipbuilding, King’s College, Newcastle upon Tyne, over a wide range of advance coefficient and at cavitation numbers from the low values corresponding to twin-screw passenger-liner propellers up to the higher values for a large single-screw cargo ship. The variations studied are pitch-ratio, distribution of area and distribution of pitch, and, to some extent, changes in blade-section shape, and the paper includes design charts in the usual B p − δ form, together with simple cavitation diagrams derived from the test results.

Most of the work has been carried out in a uniform stream, but the final section relates to tests made in a radially variable stream velocity.

The paper also considers specific designs at each end of the merchant-ship range; four- and five-bladed propellers for a passenger liner; five- and six-bladed propellers for a large tanker. Som observations of variable-wake tests are given.