An evaluation method of trial tests will be presented which is based on propeller characteristic functions provided by open water tests.Main reference quantity is the rate of revolutions which is constant during one t...An evaluation method of trial tests will be presented which is based on propeller characteristic functions provided by open water tests.Main reference quantity is the rate of revolutions which is constant during one trial double run and reliably to measure and,furthermore,the basic quantity of the mathematical adjustment of the hydrodynamically coupled test quantities by means of regression analysis.Using this physical plausible analysis of the trial test data and the propeller open water diagram an evaluation of current speed and ship’s speed through the water is possible.Assumed that thrust deduction fraction and relative rotative efficiency are scale independent,speed and power under contract conditions may be calculated at constant propeller speed where the results are corrected with respect to wind and waves using the linear dependance of speed and power at moderate differences of propeller load.展开更多
文摘An evaluation method of trial tests will be presented which is based on propeller characteristic functions provided by open water tests.Main reference quantity is the rate of revolutions which is constant during one trial double run and reliably to measure and,furthermore,the basic quantity of the mathematical adjustment of the hydrodynamically coupled test quantities by means of regression analysis.Using this physical plausible analysis of the trial test data and the propeller open water diagram an evaluation of current speed and ship’s speed through the water is possible.Assumed that thrust deduction fraction and relative rotative efficiency are scale independent,speed and power under contract conditions may be calculated at constant propeller speed where the results are corrected with respect to wind and waves using the linear dependance of speed and power at moderate differences of propeller load.
