Aero-mechanical Optimization Design Of A Civil Aircraft’s High-lift System

An appropriate and reliable high-lift system plays an important role in achieving goodperformance during modern civil aircraft takeoff and landing. But the combination of its complexityin flow physics, geometry, and system support and actuation lead high-lift to difficulty in aircraftdesign. The purpose of this thesis is to design a high-lift system by using aero-mechanicaloptimization design exploration for aircraft’s engineering application.Firstly, the overall design of high lift devices, which consist of aerodynamic performance, thelayout on spanwise and chordwise direction, was proposed based on relevant aircraft parameters.In two-dimension high-lift design, a parametric design/optimization exploration for atwo-dimensional three-element airfoil consisted of a slat, a main wing, and a flap was carried out.This exploration described single-element airfoil shape parameterized by NURBS curves, andselected three-element airfoil configurations with excellent aerodynamic performance both fortake-off and landing condition by using CFD and optimization algorithms.According to spanwise and chordwise layout, a number of key cross-sections were selected togenerate three-dimensional high-lift in accordance with the three-element airfoil optimization results.And three-dimensional high-lift aerodynamic characteristics were analyzed to make sure it wouldmeet the given aerodynamic target.In the final part of this thesis, flap movement track was optimized and the driving mechanismsfor slat and flap were designed. The possible twist and interference problems can be avoided and theaerodynamic performance will transform smoothly during slat and flap motion as a result of motionsimulation and CFD analysis.The aerodynamic performance analysis and motion simulation show that this high-lift satisfied thepredetermined design requirements, and the aero-mechanical optimization design exploration forcivil aircraft’s high-lift system has a certain value for engineering application.