Parametric study of airfoil performance at low reynolds for applications to the project of rotary blades

Abstract

This research project proposes the use of the software XFOIL to study the flow in the boundary layer of an airfoil at the low Reynolds number regime, in association with the method Blade Element Momentum to calculate the aerodynamic loading and parameters for rotary blades performance under hover flight and viscous flow conditions. The software XFOIL will be used to study the laminar separation bubble over the upper-surface of both Eppler 387 (E387) e FX 63-137 airfoils, which are projected for applications at low Reynolds number, with angles of attack ranging from 18 to -2 degrees and Reynolds number of 200.000, 350.000 and 500.000. The results obtained by numerical simulations will be verified based on numerical and experimental results published in the literature. In a second step, the software XFOIL will be used to calculate the lift and drag coefficients for flow with Reynolds number ranging from 100.000 to 1.000.000. The method Blade Element Momentum, developed as an in-house code, will be applied to study the wake induced by rotary blades, to calculate forces and moments and to evaluate the aerodynamic performance of the airfoils E387, FX 63-137 e NACA-0015, based on project's geometric parameters and operational conditions. The results obtained with the E387 e FX 63-137 airfoils will be compared with experimental results of a rotor equipped with a NACA-0015 symmetric airfoil. This study is part of a research project aiming at developing a Rotary blade mechanism to be applied to bench tests.