Vibration Analysis using Finite Element Analysis (FEA): An Evaluation of Pico-Tubular Bulb Type Turbine Blades Fabricated in Composite Materials

Abstract

Tubular turbines have been widely employed and evolved fast when its introduction in the 1930s due to their strong technical and economic qualities and application. Because its performance and structure differ from those of ordinary vertical shaft units, local and international academics worked extensively on research techniques and technological means using numerical simulation and model testing. The transmissions of a high quantity of power, which may cause unwanted vibrations that reduce efficiency, increase wear, and, in the worst-case scenario, cause serious damage. In this paper, the material propose in order to substantiate that the random excitations and excess vibration of the pico-turbine can be prevented is the use of CFRP (carbon fiber reinforced polymer) and PLA (polylactic acid). In this paper, ANSYS® Mechanical modal simulation is used to evaluate the structures’ robustness behavior of the composite materials that were used as the main material in the fabrication of turbine blades for bulb-type turbine application. The use CFD simulation in SOLIDWORKS® is needed to examine the pressure fluctuation caused by unsteady flow that can contribute in the unwanted pulsation and to conform the modal simulation results. To validate the results, pressure pulsation experimentation is conducted to evaluate the fluctuation of the pressure affecting the blades or in the rotating region and it is analyzed through frequency response domain. Hence, in this paper, it is proven that the vibration behavior of the material is acceptable since the resulting natural frequency provides resulting stress, strain, and deformation that is allowable and below its ultimate tensile strength.