【作者】 郑健；

【导师】 周长省；

【作者基本信息】 南京理工大学 ， 兵器发射理论与技术， 2009， 博士

【摘要】 随着现代飞行器的飞行速度不断增加,高超声速气动力和气动加热已经成为高超声速飞行器发展的重要研究课题。本文开展了弧形翼及翼-身组合体在超高速下的空气动力学特性研究。采用计算流体动力学软件FLUENT对弧形翼及翼-身组合体在超高速下的三维绕流流场进行了数值模拟,对不同滚转角下的弧形翼-身组合体进行了风洞试验研究,同时对弧形翼在超高速下的气动加热过程进行了数值模拟。首先建立了研究弧形翼在超高速下空气动力学特性的数学模型。数值方法采用三维守恒型、可压缩、非定常粘性流体雷诺平均N-S方程为控制方程,离散格式采用二阶迎风格式。针对高超声速流下的数值模拟,引入了AUSM+格式,降低了数值耗散性,提高了间断分辨率和计算精度。湍流模型采用雷诺应力湍流模型。采用了非一致网格技术建立了弧形翼-身组合体的网格模型,既满足了不同分区网格的疏密要求和粘性计算要求,又降低了计算网格量。采用本文所研究的计算程序和数值格式,对弧形翼在超高速下的三维绕流流场进行了数值模拟。获得了合理的流场结构信息和气动力数据,重点分析了弧形翼在零攻角下产生升力的机理,以及弧形翼气动力特性随马赫数、攻角的变化规律,同时研究了翼前缘削尖角角度、翼的曲率对弧形翼气动力特性的影响。对弧形翼-身组合体三维绕流流场进行了超高速下的数值模拟,详细研究了远场流场参数、攻角等因素对超高速弧形翼-身组合体流场结构及气动力特性的影响规律。对弧形翼-身组合体进行了不同滚转角下的超声速风洞试验,获得了合理的风洞试验纹影图和风洞试验数据,与数值模拟得到的流场结构波谱图和气动力计算结果进行比较,两者比较吻合,验证了本文所研究的数值计算程序是正确可行的,计算精度具有较高的可信度。建立了弧形翼在超高速下气动加热的计算模型,把形式上相对独立的流场和结构的控制方程联系起来,采用流场、热、结构耦合的-体化数值模拟方法求解了弧形翼超高速下的气动加热过程,获得了弧形翼在不同马赫数、攻角下的气动加热特性。本文的研究工作对我国进行大长细比、超高速的飞行器空气动力学问题研究具有一定的指导意义,同时为弧形翼的理论研究和工程应用设计提供了参考依据。更多还原

【Abstract】 With the continuous increase of modern vehicle’s flight velocity, it has become the important study that of hypersonic aerodynamics and aerodynamic heating. The research on aerodynamic characteristics of wrap-around fin and wing-body combination was carried out at super high speeds in this dissertation. Three dimensional flow over wrap-around fin and wing-body combination and aerodynamic heating process were simulated numerically in super high speeds using FLUENT. Wind tunnel test of projectile with wrap-around fin at different roll angle was finished also.Mathematic model for investigating wrap-around fin’s aerodynamic characteristics at super high speeds was established. The time-dependent compressible Reynolds average Navier-Stokes equations were used as governing equations. Second-order upwind scheme was adopted for the convective fluxes discretization. For numerical simulation of hypersonic flow, the AUSM+ scheme was introduced in order to reduce numerical dissipation and improve the resolution of shock discontinuities and computational accuracy. The Reynolds stress turbulent model was considered in this dissertation. The conformal mesh technology was applied in modeling mesh of wrap-around fin-body combination. It both satisfies the requirement of different zonal mesh density and viscous calculation, and decreases the amount of computational mesh.Three dimensional flow over wrap-around fin was simulated numerically at super high speeds with computational program and numeric scheme studied in this dissertation. Reasonable flowfield structure information and aerodynamic data were obtained by numerical simulation. Mechnism of producing lift of wrap-around fin at zero angle of attack was analyzed selectively. Change law of wrap-around fin’s aerodynamic characteristics as a function of Mach number and angle of attack was investigated. The effects on aerodynamic performance of fin’s leading edge nib angle and curvature were researched simultaneously.Numerical simulation of flow over wrap-around fin-body combination was done at super high speeds. The influences of inflow Mach number and angle of attack on wrap-around fin-body combination’s flowfield and aerodynamic characteristics were studied in detail. Reasonable flow strcture and experimental data were obtained by wind tunnel test. Numerical result was almost in the same with experimental data. The wind tunnel test validates the correctness and reliability of the numerical calculation program studied in this dissertation.Computational model for studying the aerodynamic heating of wrap-around fin was built. Combinating the flow and structure governing equations which were relatively independent in form, aerodynamic heating process of wrap-around fin was solved at super high speeds using integration numerical simulation coupled flow, thermal and structure. Aerodynamic heating performance of wrap-around fin was achieved with different Mach number and angle of attack.Research work in this paper has an instructing meaning of investigating flight vehicle’s aerodynamic characteristics with long ratio of slenderness in super speed. It supplys a foundation of wrap-around fin’s basic research and engineering application design at the same time.The study method and result has guiding significance for investigating flight vehicle’s aerodynamic characteristics with long ratio of slenderness at super high speeds. It provides the reference foundation for wrap-around fins’ basic research and engineering application design.更多还原