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基于Fluent的某小型无人机机翼布局对比研究

2018-04-13张东升魏江鹏文程祥

现代电子技术 2018年8期

张东升 魏江鹏 文程祥

摘 要: 运用Solidworks对某规格的前掠翼、平直翼和后掠翼进行三维建模,利用CFD软件,采用三维N?S方程及Spalart?Allmaras涡粘湍流模型对前掠翼、平直翼和后掠翼的空气动力学特性进行研究,每间隔2°计算迎角从0°~38°时的不同情况,对比分析各自的优势和不足,最后给出结论,为低速小型无人机的机翼布局选型提供了理论依据。计算结果表明低速飞行下平直翼布局升力系数较大,没有气流分离的情况,这种布局较为合理。

关键词: 前掠翼; 平直翼; 后掠翼; 气动分析; 失速; Solidworks

中图分类号: TN876?34 文献标识码: A 文章编号: 1004?373X(2018)08?0147?04

Abstract: Solidworks is used to build 3D models for forward swept wing, straight wing and backward swept wing of a certain specification. The CFD software, three dimensional N?S equation and Spalart?Allmaras eddy viscosity turbulence model are adopted to study the aerodynamic characteristics of forward swept wing, straight wing and backward swept wing. Angles of attack from 0° to 38° are calculated at an interval of every 2°, whose advantages and disadvantages are contrasted and analyzed so that the conclusion can be finally drawn to provide a theoretical basis for wing layout selection of a low?speed small UAV. The calculation results show that the lift coefficient of straight wing layout is larger at a low speed flight as there exists no air separation, and the straight wing layout is more reasonable.

Keywords: forward swept wing; straight wing; backward swept wing; aerodynamic analysis; stall; Solidworks

无人机可完成某些载人飞机无法完成的特殊任务,使得无人机的发展受到空前的关注,各个国家纷纷投入大量资源研制新型多功能无人机 [1?3]。对于小型无人机等低速飞行的飞行器而言,机翼布局是一项值得研究的课题。现设计一款小型倾转旋翼无人机,同时具有旋翼与固定翼,为了确定固定翼布局,利用Fluent对不同机翼进行空气动力学仿真,进一步探讨机翼布局气动特性[4?6],通过对比结果选出合适的机翼布局。NACA翼型有着良好的升力特性[7],本文将对基于NACA4415翼型的前掠翼、平直翼与后掠翼进行升力特性对比,给出小型无人机机翼布局的设计参考,翼型如图1所示。

1 模型的建立与网格划分

机翼翼展均为1 600 mm,现取半个机翼进行流体计算。翼根部弦长300 mm,翼尖部弦长200 mm,前掠翼前缘前掠角为17°,后掠翼前缘后掠角为7°。计算区域采用Gambit划分的非结构网格,划分网格时进行了区域加密,对机翼周围流场的网格进一步加密。……

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