Experimental estimation for pressure fluctuation on ship stern induced by cavitating propeller using cavity shape measurements

摘要

Authors have recently developed a combination-line charge-coupled device camera-based method for measuring three-dimensional shapes that is faster and more accurate than conventional methods. Furthermore, the developed system can measure cavity shapes on a model propeller through the experiments in the large cavitation tunnel of NMRI. However, it is necessary to verify how much accuracy the system has in the cavity shape measurement. In this paper, we verify the accuracy through a comparison of the pressure fluctuation estimated by the cavity volume and measured by the pressure sensor. In the estimation, since the unsteady cavity is replaced by a spherical bubble moving with varying radius, the pressure fluctuation induced by the sphere is calculated. The pressure fluctuation is estimated by applying the proposed method to experimental data of the cavity shape The pressure fluctuation estimated by the proposed method is in good agreement with the pressure fluctuation measured by pressure sensors. This result also showed that the cavity shape measurement system developed by the authors has sufficient accuracy.