展向动量测定法与前掠翼流动机理研究  

Flow mechanism of forward-swept wing with spanwise momentum method

作　　者：薛榕融[1] 叶正寅[1] 王刚[1] 武洁[1] XUE Rongrong;YE Zhengyin;WANG Gang;WU Jie(School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西北工业大学航空学院,陕西西安710072

出　　处：《空气动力学学报》2018年第5期736-742,共7页Acta Aerodynamica Sinica

基　　金：国家自然科学基金(11272264)

摘　　要：为揭示前掠翼与后掠翼的流动差异,研究前掠翼流动的特点和机理,设计了可进行直接比较的具有相同翼型剖面、相同展弦比、无根梢比的前掠45°(Λ=-45°)与后掠45°(Λ=45°)机翼模型,采用基于雷诺平均N-S方程流场求解器对前掠和后掠翼低速纵向气动性能进行数值模拟计算,并提出了展向动量测定法前掠翼流动机理进行了深入分析,研究结果表明:1)前掠翼展向动量输运使得升力向翼根汇聚,前掠翼展向升力分布更接近于椭圆分布,致使前掠翼诱导阻力更小;2)黏性对前掠翼的流场计算影响很大,文献中基于势流理论得到前掠翼比后掠翼气动性能好的结果是不准确的;3)在小迎角时,前掠翼气动效率与后掠翼相当,仅在最大升阻比迎角时前掠翼优于后掠翼,中等迎角下前掠翼翼根分离导致气动效率下降,但前掠翼具有更好的大迎角失速特性,有利于前掠翼大迎角飞行;4)相同总升力的情况下,前掠翼的翼根弯矩只有后掠翼的翼根弯矩的89.4%,采用前掠翼更有利于减轻机翼的结构重量。Simplified models are designed to investigate the influence of swept angle on aerodynamic characteristics of the forward and backward swept wings.For both forward-and backward-swept wing models,the wing planform has a untapered leading-and trailing-edge sweep of-45/45 degree.The wing span of 4 meter,in conjunction with a chord length of 1 meter,yields an aspect ratio of 4.A spanwise momentum method is proposed to analyze force coefficient difference and flow mechanism of forward and aft-swept wing.Results demonstrate that:1)more lift is produced at forward-swept wing root due to the spanwise momentum accumulation at forward-swept wing root,resulting in an elliptical-like lift distribution of forward-swept wing and less induced drag on forward swept wing;2)the conclusion that forward swept wing has better lift performance based on potential flow theory from references is not accurate because viscous effects fiercely decreases aerodynamic efficiency of the forward-swept wing;3)at low angle of attack,the ratios of forward-and aft-swept wing are at the same level,except that the forward-swept wing has a better aerodynamic efficiency at the maximum ratio position;at middle angle of attack,the forward-swept wing root separation due to boundary layer accumulation significantly degrade its performance,however,the lift curve of the forward-swept wing gradually changes at the stalling angle,which reflects its better stall performance;4)compared with the aft-swept wing,the forward-swept wing produces 89.4%root bending torque for the equivalent lift,which is helpful to reduce wing structure weight.

关 键 词：展向动量测定法 前掠翼 流动机理 气动效率 翼根弯矩 

分 类 号：V211[航空宇航科学与技术—航空宇航推进理论与工程]