前翼对飞机纵向气动特性和机翼载荷影响研究

利用ARGON和MGAERO计算了三翼面布局飞机气动特性和机翼载荷,给出了有前翼、无前翼布局全机气动特性和机翼环量分布。研究分析了前翼对全机气动特性、机翼分布载荷的影响规律,得到了一些重要的结论,可用于飞机型号设计。     

一种新的动网格方法及其应用

 介绍了一种新型的动网格方法。该方法以Delauney图为基础进行整个网格的移动变形：首先是生成满足Delauney特性的Delauney图;然后把对网格移动的特性映射到Delauney图的移动上;最后把网格点在Delauney图以映射的方式进行重新定位而得到新的网格点坐标,从而得到移动后的网格。该方法不需要迭代,因而效率高,并且能适用于任意拓扑结构的网格。以翼身组合体的机翼颤振、翼身融合体的变体过程的非定常流动等为例来说明该方法的高效性及适用面广等特点。     

Design and experimental study of a new flapping wing rotor micro aerial vehicle

A three-wing Flapping Wing Rotor Micro Aerial Vehicle (FWR-MAV) which can perform controlled flight is introduced and an experimental study on this vehicle is presented. A mechanically driven flapping rotary mechanism is designed to drive the three flapping wings and generate lift, and control mechanisms are designed to control the pose of the FWR-MAV. A flight control board for attitude control with robust onboard attitude estimation and a control algorithm is also developed to perform stable hovering flight and forward flight. A series of flight tests was conducted, with hovering flight and forward flight tests performed to optimize the control parameters and assess the performance of the FWR-MAV. The hovering flight test shows the ability of the FWR-MAV to counteract the moment generated by rotary motion and maintain the attitude of the FWR-MAV in space; the experiment of forward flight shows that the FWR-MAV can track the desired attitude.     

机翼跨声速抖振数值模拟及模态分析

绕机翼的跨声速抖振流动是典型的复杂不稳定流动，对其非定常特性及失稳机制的研究具有重要的工程和学术价值。通过非定常雷诺平均Navier-Stokes（URANS）仿真方法和动模态分解（DMD）分析手段，研究了CRM（Common Research Model）等典型机翼的跨声速抖振流动特性及其主要失稳模态。数值仿真结果表明机翼的跨声速抖振表现为多失稳模式下的宽频特性。除了激波的弦向失稳，还会伴随发生激波的展向失稳，它们都表现为低频特性。翼梢处的高频响应可能是由激波诱导的低频失稳与翼尖涡相互耦合形成。DMD分析结果显示机翼展长和后掠因素诱导了激波展向失稳模态。本研究对抖振流动的物理建模、控制及理解相关的气动弹性现象具有指导意义。     

Flight dynamics characteristics of canard rotor/wing aircraft in helicopter flight mode

The aerodynamic layout of the Canard Rotor/Wing(CRW) aircraft in helicopter flight mode differs significantly from that of conventional helicopters. In order to study the flight dynamics characteristics of CRW aircraft in helicopter mode, first, the aerodynamic model of the main rotor system is established based on the blade element theory and wind tunnel test results. The aerodynamic forces and moments of the canard wing, horizontal tail, vertical tail and fuselage are obtained via theoretical analysis and empirical formula. The flight dynamics model of the CRW aircraft in helicopter mode is developed and validated by flight test data. Next, a method of model trimming using an optimization algorithm is proposed. The flight dynamics characteristics of the CRW are investigated by the method of linearized small perturbations via Simulink. The trim results are consistent with the conventional helicopter characteristics, and the results show that with increasing forward flight speed, the canard wing and horizontal tail can provide considerable lift,which reflects the unique characteristics of the CRW aircraft. Finally, mode analysis is implemented for the linearized CRW in helicopter mode. The results demonstrate that the stability of majority modes increases with increasing flight speed. However, one mode that diverges monotonously,and the reason is that the CRW helicopter mode has a large vertical tail compared to the conventional helicopter. The results of the dynamic analysis provide optimization guidance and reference for the overall design of the CRW aircraft in helicopter mode, and the model developed can be used for control system design.     

In-plane corrugated cosine honeycomb for 1D morphing skin and its application on variable camber wing

A novel 0-Poisson’s ratio cosine honeycomb support structure of flexible skin is proposed. Mechanical model of the structure is analyzed with the energy method, finite element method (FEM) and experiments have been performed to validate the theoretical model. The in-plane characteristics of the cosine honeycomb are compared with accordion honeycomb through analytical models and experiments. Finally, the application of the cosine honeycomb on a variable camber wing is studied. Studies show that mechanical model agrees well with results of FEM and experiments. The transverse non-dimensional elastic modulus of the cosine honeycomb increases (decreases) when the wavelength or the wall width increases (decreases), or when the amplitude decreases (increases). Compared with accordion honeycomb, the transverse non-dimensional elastic modulus of the cosine honeycomb is smaller, which means the driving force is smaller and the power consumption is less during deformation. In addition, the cosine honeycomb can satisfy the deform- ing requirements of the variable camber wing.     

一种机翼弯剪载荷包线近似计算方法

在机翼静强度初步设计中,为了快速准确地得到其载荷包线并用于确定翼盒结构基本参数,提出一种近似计算方法。通过比较多种重量估算方法,发现三角形分布能较好地拟合机翼重量。考虑到大型民用运输机飞行临界过载和集中载荷等特性,综合利用Schrenk升力分布和三角形重量分布,得到在飞行载荷下的一种近似计算机翼剪力和弯矩载荷包线方法。通过分析两机翼风洞试验数据得到的机翼剪力和弯矩包线,证明该近似方法是可行的。     

公务机机翼气动外形优化研究

随着世界经济贸易的发展,轻中型公务机愈发受到客户的青睐。为了进一步提升高速涡扇公务机的总体气动性能,本文采用基于全速势方程（TRANAIR）的流场快速求解方法,集成序列二次规划（SQP）优化算法和类函数/型函数变换（CST）自由变形（FFD）技术,对某轻中型高速涡扇公务机机翼进行多点优化设计研究,并对优化结果进行对比分...     

民航客机最佳机翼面积的优化方法

分析了民航客机燃油效率的影响因素,将气动阻力进行分解,推导出了以巡航效率为优化目标的最佳机翼优化方法。算例表明,无论是在飞机的方案设计阶段,还是在详细设计阶段,方法都是适用的。方法不仅可用于最佳机翼面积的优化工作,在详细设计阶段,还可用于检验飞机的气动优化设计是否偏离飞机的优化目标,以及检验飞机的最佳巡航航程指标是否与最佳燃油效率匹配。     

基于结构网格的操纵面嗡鸣数值研究

利用无限插值法生成结构化动网格,耦合求解欧拉方程与结构方程,分别模拟了二维带操纵面翼型以及三维NASP机翼周围跨音速流动。对二维带操纵面翼型嗡鸣发生时的流场进行了分析,发现操纵面上的激波后会产生巨大的分离区,且分离区的变化过程滞后于激波变化过程,认为缝隙的存在对嗡鸣发生有促进作用;对三维NASP机翼的研究发现操纵面质量比的增加可以延缓嗡鸣发展。