Solution to Optimize the Airfoils Shapes Placed Into a Supersonic Viscous Flow

V. Radulescu
{"title":"Solution to Optimize the Airfoils Shapes Placed Into a Supersonic Viscous Flow","authors":"V. Radulescu","doi":"10.1115/IMECE2018-86781","DOIUrl":null,"url":null,"abstract":"To improve the airfoils performances placed in supersonic flow is proposed a method of optimization for their shapes, in order to minimize the effect of the landing vortices. The theoretical modeling starts with the Navier-Stokes equations applied for thin layers, supplemented with additional conditions related to the profile shape. For a proper estimation of efficiency and responses at different flow regime’s conditions, were considered four aerodynamics airfoils, with different shapes and functioning characteristics. Two of them are special shapes of supersonic profiles and the other two deduced by theoretical assessments with an efficient behavior at high Reynolds numbers. The main purpose of this selection was to identify the essential aspects needed to be considered in numerical modeling of the airfoil’s wing shapes, as to assure an optimization of their behavior for different flow conditions. In the supersonic flow, the cross-sections of the wings are thin profiles, mainly symmetric, as to reduce the drag coefficient and to maximize, as possible, the lift coefficient. A supplementary method for the shape calculation of the aerodynamic profiles with small curvature, based on the Fredholm integral equation of the second kind, with a good behavior in the supersonic flow, is presented. Some aspects referring to unsteady flows and air compressibility are considered, as to simulate as much as possible the real, natural conditions. All profiles were tested, firstly, into a subsonic wind tunnel at incidences between 00 – 40 for different values of wind velocity, and secondly, into a supersonic wind tunnel, at the same incidences. The objective was to better understand and analyze the main factors, which influence the aerodynamic of shapes with curvature, and to assure an optimization of their behavior. The purpose of testing these profiles was to estimate a solution to improve the main characteristics, especially into the trailing and leading edges zones. There were also considered the effects of the attack angle, the influence of the wind velocity, air viscosity, and the shape’s curvature, on the vortices development. The obtained results allow a better functioning in supersonic flow regime, by eliminating the adverse pressure gradient and the boundary layer separation, assuring an optimum behavior especially into the leading edge zone.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Volume 1: Advances in Aerospace Technology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1115/IMECE2018-86781","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

To improve the airfoils performances placed in supersonic flow is proposed a method of optimization for their shapes, in order to minimize the effect of the landing vortices. The theoretical modeling starts with the Navier-Stokes equations applied for thin layers, supplemented with additional conditions related to the profile shape. For a proper estimation of efficiency and responses at different flow regime’s conditions, were considered four aerodynamics airfoils, with different shapes and functioning characteristics. Two of them are special shapes of supersonic profiles and the other two deduced by theoretical assessments with an efficient behavior at high Reynolds numbers. The main purpose of this selection was to identify the essential aspects needed to be considered in numerical modeling of the airfoil’s wing shapes, as to assure an optimization of their behavior for different flow conditions. In the supersonic flow, the cross-sections of the wings are thin profiles, mainly symmetric, as to reduce the drag coefficient and to maximize, as possible, the lift coefficient. A supplementary method for the shape calculation of the aerodynamic profiles with small curvature, based on the Fredholm integral equation of the second kind, with a good behavior in the supersonic flow, is presented. Some aspects referring to unsteady flows and air compressibility are considered, as to simulate as much as possible the real, natural conditions. All profiles were tested, firstly, into a subsonic wind tunnel at incidences between 00 – 40 for different values of wind velocity, and secondly, into a supersonic wind tunnel, at the same incidences. The objective was to better understand and analyze the main factors, which influence the aerodynamic of shapes with curvature, and to assure an optimization of their behavior. The purpose of testing these profiles was to estimate a solution to improve the main characteristics, especially into the trailing and leading edges zones. There were also considered the effects of the attack angle, the influence of the wind velocity, air viscosity, and the shape’s curvature, on the vortices development. The obtained results allow a better functioning in supersonic flow regime, by eliminating the adverse pressure gradient and the boundary layer separation, assuring an optimum behavior especially into the leading edge zone.
解决方案,以优化翼型形状放置到一个超音速粘性流动
为了提高超声速流动中翼型的性能,提出了一种优化翼型形状的方法,以减小着陆涡对翼型的影响。理论建模从应用于薄层的Navier-Stokes方程开始,辅以与剖面形状相关的附加条件。为了正确估计不同流型条件下的效率和响应,考虑了四种不同形状和功能特性的气动翼型。其中两种是超声速型的特殊形状,另外两种是通过理论计算推导出来的,在高雷诺数下具有有效的行为。这一选择的主要目的是确定在翼型的机翼形状的数值模拟需要考虑的基本方面,以确保其行为的不同流动条件的优化。在超声速流动中,机翼的横截面是薄的,主要是对称的,以减少阻力系数和最大化升力系数。提出了一种基于第二类Fredholm积分方程的小曲率气动型面形状计算的补充方法,该方法在超声速流动中具有良好的性能。考虑了非定常流动和空气可压缩性的一些方面,尽可能地模拟真实的自然条件。在不同的风速值下,对所有剖面进行了亚声速风洞和超音速风洞的测试。目的是更好地理解和分析影响曲率形状气动特性的主要因素,并确保其性能的优化。测试这些剖面的目的是评估改善主要特性的解决方案,特别是在尾缘和前缘区域。还考虑了攻角、风速、空气粘度和形状曲率对旋涡发展的影响。通过消除逆压梯度和边界层分离,所获得的结果允许在超音速流动状态下更好地发挥作用,确保了最佳行为,特别是在前缘区域。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信