船舶のプロペラレーシングに関する研究

抄録

This paper deals with a new statistical prediction method for the propeller racing of ships sailing in rough seas. The propeller racing is one of the most important sea keeping quality in relation to the safety of main engine and shafting system. The trend of the racing has been investigated mainly in order to estimate allowable maximum propeller diameter, operability of ocean-going ships etc.. In those studies, the propeller racing generally and mainly means the situation (propeller exposed) in which the relative motion amplitude between ship hull and wave surface would exceed a depth of point in rotary disk propeller. Therefore, it seems that the magnitude of the amplitude and its exceeding frequency have been examined as a principal subject of study as usual. However, the time during which the amplitude exceeds a depth of point, that is, the propeller exposes in the air over sea surface, must be also one of most important factor affecting the trend of propeller racing. Then, this paper proposes a new practical method for estimating the time lasting of exposed propeller related to propeller racing in rough confused seas on the basis of the statistics.