It is a fact that specifying numerically the natural frequencies of a marine propeller rotating in a water environment is quite difficult due to the problem that arises from the inability to consider the effect of rotation and pressure distribution in the modal acoustic module of the software. In the present study, an alternative approach to the experimental studies is proposed to come through this problem that enables researchers to predict numerically the change in natural frequency of a three-bladed marine propeller. The method based on the fluid-structure interaction (FSI) technique uses the modal stiffness and the modal mass that is calculated from the numerical analysis of a rotating marine propeller in air and then considers the effects of the added mass by utilizing the frequency reduction ratio (FRR) and finally defines the natural frequencies of the rotating propeller in the water. The simulations revealed that the natural frequencies of the propeller decrease substantially in water due to the added mass and the reduction in the natural frequencies with respect to frequencies in the air is 28% for the first, 34% for the second, and the third. Since natural frequencies of a rotating propeller in water cannot be simulated the equivalent stiffness and masses were defined for each frequency from the analyses of propeller rotating in the air. It was concluded that the natural frequency of the propeller decreases when the propeller is placed in water for the same boundary conditions.

事实上，由于无法在软件的模态声学模块中考虑旋转和压力分布的影响而产生的问题，数值指定在水环境中旋转的船用螺旋桨的固有频率非常困难。在本研究中，提出了一种替代实验研究的方法来解决这个问题，使研究人员能够以数值方式预测三叶船用螺旋桨的固有频率变化。基于流固耦合（FSI）技术的方法是利用在空气中旋转的船用螺旋桨的数值分析计算的模态刚度和模态质量，然后利用降频比考虑附加质量的影响。 (FRR) 并最终定义旋转螺旋桨在水中的固有频率。模拟表明，螺旋桨的自然频率由于增加的质量而在水中显着降低，并且自然频率相对于空气中的频率降低了 28%，第二次和第三次降低了 34%。由于无法模拟水中旋转螺旋桨的固有频率，因此根据螺旋桨在空气中旋转的分析，为每个频率定义了等效刚度和质量。