Systematic cavitation tunnel tests for cavitation noise prediction of commercial ships using a standard series approach

This paper presents a small, but commercially representative, standard series of propeller models tested in the Emerson Cavitation Tunnel of Newcastle University using 3 members of the well-known Meridian standard series for commercial ship propellers. The members were chosen to test significant propeller design parameters from the noise radiation point of view including pitch to diameter ratio, blade area ratio, number of blades, operating conditions etc. The chosen members were tested both in open water condition as well as behind 3 different grades of axial wakes using 2D wake screens. Grading was made according to the BSRA (or BMT) wake non-uniformity criteria from the mildest to the most severe grade which results in more unstable cavitation to be experienced by a propeller. Based on the measured noise data the results were extrapolated to full-scale using an available in-house database for some real commercial vessels with the similar main particulars of the standard series of the propellers tested. The extrapolated data was compared with the average commercial shipping noise data to make a rough validation of the generated noise data. The experimental noise data presented in this study is expected to be a very useful mitigation tool that can be used to predict the noise levels in the early design stage of the commercial ship propellers, as long as the main particulars of the prospective propeller design would be in the range of the database provided.