ボラード状態のプロペラにより誘起される変動水圧について

概要

論文の詳細を見る
When a ship propeller operates at zero ship speed, known as the bollard condition, high pressure fluctuations are induced around it. In water of restricted depth pressure fluctuations could cause churning up of mud at the sea bottom and in some cases enviromental problems in harbors, canals and rivers. Since these phenomena are not fully understood and the qualitative prediction is difficult, it is necessary to study the fundamental nature of these fluctuations. In this work, the pressure fields around the model propellers operating in the bollard condition were measured. Measured results are classified into three types of fluctuating pressures as follows: (1) Periodic and low pressure fluctuations induced by the propeller blade thickness effect and the propeller loading. (2) Random and high pressure fluctuations induced by the propeller-hull vortex. (3) Unsteady and low pressure fluctuations induced by the propeller wake. Pressures due to the propeller-hull vortex were found to be the highest, while pressures due to the propeller itself and pressures due to the propeller wake were found to have almost equal magnitude. Extensive experimental data given in this paper are useful for predicting unfavorable phenomena caused by propellers operating under the bollard condition.
社団法人日本航海学会の論文
1998-09-25