Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
A Numerical Study of Rotor Hover Performance at Low Reynolds Number Flow.
Submission Author:
Gabrieli Boni , SP
Co-Authors:
Gabrieli Boni, Daniel Sampaio Souza, Carlos Pagani
Presenter: Gabrieli Boni
doi://10.26678/ABCM.COBEM2021.COB2021-0705
Abstract
The objective of this work is to apply the Blade Element Momentum (BEM) method to study the aerodynamic efficiency of rotary blades considering hovering flight and viscous flow. The numerical analysis framework applies the lift and drag coefficients, calculated with the XFOIL code as function of angle of attack within a range of low Mach numbers, to an in-house BEM code, which enables obtaining induced flow parameters and performance of rotary blades in terms of geometry and operational conditions. The NACA-0015, Eppler 387 and FX63-137 were the airfoils chosen for this study. The study is relevant in view of the increasing interests for research and development of small aircraft operating in low Reynolds number to cargo transportation, mapping, data collection etc. To obtain a strong database some adjustments has been taken in the results of the simulation, which served to predict some points that not converged and to linearize the lift coefficients. The software was also applied to conduct a brief study on the boundary layer that can be useful in future research. As a first numerical step, induced flow, lift and drag radial distributions are obtained at each blade section along the blade span, so that both the thrust force and drag moment acting over the rotor blades are obtained by simple numerical integration along the blade span. Lift and drag coefficients are necessary for the calculation of the Figure of Merit, which is a common performance parameter in literature and that at high values indicates a reduction in induced power in the rotor. Another relevant parameter is the Power Loading that the increase indicates a decrease in the power needed to generate traction. Both are efficiency parameters and relate directly to other fundamental parameters in the design of a rotating blade mechanism. It is expected the results of this research can be helpful to the development of technological mechanism for future experimental test benches and structural design of rotating blades as well.
Keywords
rotary wings, Número de Reynolds, esteira aerodinâmica
