جستجوی مقالات مرتبط با کلیدواژه "تحلیل مودال" در نشریات گروه "مهندسی دریا"

Propeller-induced vibration of a marine vessel is one of the most complex issues of fluid and structure and the interaction between them. In the present article, numerical simulations of fluid flow around the propeller are performed first and the characteristic curves of propeller hydrodynamic performance in open water conditions are plotted for various advance ratios. It is observed that the maximum relative error of numerical simulations relative to experimental data in various advance ratios is about 7%. Then, the numerical vibration simulations of the solid propeller are performed. To achieve the results independently from the computational grid, the modal analysis results for calculating the vibrational natural frequencies for five different computational grids are compared to each other. Three different popular propeller materials i.e. brass, nickel aluminum bronze, and stainless steel are considered, and the results of numerical vibrational simulations such as natural frequencies and vibrational mode shapes using the modal analysis are compared for these propellers. Quantitatively, the magnitudes of natural frequencies for stainless steel and nickel-aluminum bronze propellers are 33% and 14% more than that of the brass propeller, respectively. In other words, brass is the most vulnerable and stainless steel is the most durable propeller material against resonance.