Aircraft Propeller Design through Constrained Aero-Structural Particle Swarm Optimization

José D. Hoyos,Camilo Echavarría,Jesús H. Jiménez,Germán Urrea,Juan P. Alvarado

doi:10.3390/aerospace9030153

José D. Hoyos, Camilo Echavarría + Show 3 more

Open Access

https://doi.org/10.3390/aerospace9030153

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Abstract

An aero-structural algorithm to reduce the energy consumption of a propeller-driven aircraft is developed through a propeller design method coupled with a Particle Swarm Optimization (PSO). A wide range of propeller parameters is considered in the optimization, including the geometry of the airfoil at each propeller section. The propeller performance prediction tool employs a convergence improved Blade Element Momentum Theory fed by airfoil aerodynamic characteristics obtained from XFOIL and a validated OpenFOAM. A stall angle correction is estimated from experimental NACA 4-digits data and employed where convergence issues emerge. The aerodynamic data are corrected to account for compressibility, three-dimensional, viscous, and Reynolds number effects. The coefficients for the rotational corrections are proposed from experimental data fitting. A structural model based on Euler-Bernoulli beam theory is employed and validated against Finite Element Analysis, while the impact of centrifugal forces is discussed. A case of study is carried out where the chord and pitch distributions are compared to minimal losses distribution from vortex theory. Wind tunnel tests were performed with printed propellers to conclude the feasibility of the entire routine and the differences between XFOIL and CFD optimal propellers. Finally, the optimal CFD propeller is compared against a commercial propeller with the same diameter, pitch, and operational conditions, showing higher thrust and efficiency.

Highlights

The results show that XFOIL and Computational Fluid Dynamics (CFD) have their minimum difference at the lowest J value, which is the regime of higher Reynolds [39]
The distributions are compared against Goldstein distributions, which are the optimal pitch and chord calculated through the Euler–Lagrange equations applied to vortex theory
The aero-structural optimization carried out by the constrained Particle Swarm Optimization (PSO) proved to be a feasible solution in propeller design

Summary

Introduction

Electric propulsion is leading to a new focus in aircraft design due to the impact of green technologies on climate change. Drone flights through thinner atmospheres than earth’s one are raising new challenges on what propeller propulsion can achieve [1]. These trends require the development of multi-disciplinary optimal propeller design. The article employs the electric motor equations, a combustion propulsion model can be implemented instead [2]. Intending to optimize the electric aircraft performance, high-reliability models for propulsive systems are required. Some corrections to the basic model are implemented to capture the effects of the compressibility, Reynolds number, viscosity, and rotational effects. The rotational correction coefficients are obtained from an adjustment against experimental data [3]

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