Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Design of a platform aerodynamic balance for laminar wing force measurements
Submission Author:
João Paulo Eguea , SP
Co-Authors:
João Paulo Eguea, Gabriel Pereira Gouveia da Silva, Fernando catalano
Presenter: João Paulo Eguea
doi://10.26678/ABCM.COBEM2021.COB2021-0563
Abstract
The aviation industry's goal of designing greener aircraft relies on developing and testing new technologies in fuel, emissions, and noise. Wings designed for extended natural laminar flow (NFL) showed potential for reducing drag and improving aircraft fuel efficiency. The general and regional aviation, unmanned air vehicles (UAV), and urban air mobility (UAM) aircraft flight envelopes are favorable for NLF application. The interaction between a laminar wing and a pusher propeller may also beneficially impact the boundary layer stability. Therefore, experimental investigation on the laminar wing and pusher propeller interaction is a possibility for reaching performance improvement in these aviation market sectors. The experimental evaluation of the laminar wing and pusher propeller interaction relies on an accurate lift and drag measurement, demanding the usage of high precision aerodynamic balances. A three-platform aerodynamic balance was developed at the Experimental Aerodynamics Laboratory (LAE) in the Department of Aeronautical Engineering of the University of São Paulo (EESC-USP) to measure aerodynamic forces variations on a laminar wing due to the pusher propeller operation. The aerodynamic balance platforms are connected by four pairs of aluminum sheets equipped with two strain gauges on each set. The two sheet sets connecting the bottom and middle platforms measure the force parallel to the model chord. The force perpendicular to the model chord is measured by the sheets connecting the central and the top platforms. The chosen design enables measuring lift and drag independently and minimizing the forces and moments cross effect. Also, the sheet sets connections use bolted unions, allowing the exchanging of them according to the expected aerodynamic loads. The sheet dimensions were designed based on the S-shaped beam theory equations and validation using finite element method (FEM) simulations using Ansys Workbench. The FEM simulations showed that the aerodynamic balance measures the laminar wing forces with less than a 4% difference between applied and measured loads. The fabricated balance will be instrumented, calibrated, and used on the laminar wing and pusher propeller investigation.
Keywords
wind tunnel testing, Laminar flows, aerodynamic balance, Finite Element Analysis
