翼端渦の解像を考慮したCFD によるプロペラキャビテーションの数値シミュレーション

抄録

Marine propellers are operating in the unsteady ship wake flow, which causes the repeat of cavitation occurrence and disappearance. Such cavitation causes the serious vibration and erosion problems. Therefore, the decrease of the erosion risk is one of the very important issues in the propeller design. Especially, latest propeller design for high efficiency is based on detail estimation of cavitation performance. It is necessary to estimate the process of cavitation disappearance related to both blade cavitation and tip vortex cavitation near the very local tip region for the evaluation of the erosion risk.Recently, RANS method becomes the common useful design tool for the analysis of the flow field around marine propellers, and the application to the cavitation simulation is highly expected. It is thought that it becomes an effective method for the evaluation of the erosion risk, if it may simulate the blade cavitation and the tip vortex cavitation in detail.First of all, numerical simulation of the tip vortex of the DTMB P4119 propeller in non-cavitating condition was performed in order to examine the effectiveness of the adaptive mesh generation. Numerical results of flow field behind the propeller were compared with LDV measurement results.Finally, the cavitation simulation including tip vortex for Seiun Maru .I propellers was performed by and the cavitation patterns were compared with the experiments.