In order to investigate the unsteady flow frequency domain performances of an axial flow compressor at different mass flow , rotating speed and blade row spacing , plus inlet flow distortion , and considering aerodynamic characteristics and stability of the compressor , the low speed research compressor ( lsc ) at college of energy and power in nuaa is used to carry out the experiment studies . a large amount of test data has been gained through dynamic pressure transducers embedded in the stator blades at the tip , middle and hub section , then fast fourier transform algorithm ( fft ) is applied to calculate the frequency data 为探讨轴流压气机在工作流量、工作转速及动?静叶排轴向间距变化时的叶片排流场非定常频谱特性变化规律，并耦合进气畸变的影响，同时与压气机气动性能和气动稳定性相关联，作者利用南京航空航天大学能源与动力学院的低速大尺寸轴流压气机( lsc )试验器，采取在静子叶片表面埋入动态压力传感器的实验方法，对叶尖、叶中和叶根三个截面的动态压力进行了测量，获得了大量的可靠的实验数据。
In order to study the effect of the number of vehicle and inter - vehicle distance on the aerodynamic characteristics of vehicle platoon in intelligent transportation systems ( its ) , a single vehicle is simulated first and its results are compared with that of wind tunnel test 摘要为了研究车辆前后间距和车辆数目对智能交通系统中队列行驶车辆气动特性的影响，首先对单辆车进行数值模拟，并将模拟结果与风洞试验结果进行对比，然后对两辆车在5种不同间距下以及3 ~ 7辆车在固定间距下队列行驶的情况分别进行了数值模拟及分析。
It is necessary to study the unsteady nonlinear aerodynamic characteristics of a wig flying in air with disturbed waves for the design of high - performance wig vehicle , especially for the subject that how to improve the safety , maneuver ability near sea wave , and economics of the wig flying over sea waves 研究地效翼在风浪扰动气流场中掠海飞行的非定常气动力问题，对于高性能地效翼船的设计，特别是对于提高地效翼船在风浪中飞行的安全性，操纵性以及经济性都是十分重要的。
Compared with a delta wing aircraft , the double - delta wing configuration has better aerodynamic performance at high angles of attack . an operational analysis was introduced as a method for evaluating training effectiveness of trainer aircraft . approaches to the engineering estimation of aerodynamic characteristics for aircraft with a double - delta wing configuration were studied , and the procedures for determining aircraft performance indices formulated . taking training effectiveness as the objective function and geometric parameters of the wing platform as design variables , through a numerical multivariate optimization arithmetic , the conceptual design optimization for a certain fighter trainer aircraft with double - delta wing configuration was carried out under the constraints of tactical and technical requirements and interrelated geometry . agreement of a calculation example with engineering practice indicates that the optimal design has higher training effectiveness than the baseline design , and in addition , improves the structural force - bearing conditions 双三角翼气动布局比三角翼飞机具有更好的大攻角空气动力特性.引入了评估教练机训练效能的作战分析法,研究了双三角机翼布局飞机空气动力特性的工程计算途径以及飞机性能指标的确定方法.以训练效能作为目标函数并选取机翼平面形状的几何参数为设计变量,采用多变量数值寻优方法,在战术技术指标及相关几何约束条件下,对某高级教练机的双三角机翼气动布局方案进行了优化选择.算例表明最优方案不仅比原准方案具有更高的训练效能,还改善了结构的受力情况,与工程实践吻合
The aerodynamic characteristics of a projectile with wrap around fins are studied systematically in this paper , as follows : 1 . the lift coefficients 、 drag force coefficients 、 pitch moment coefficients 、 pitch damping moment derivatives and roll damping moment derivatives are obtained from engineering calculation through looking wrap around fins as flat fins of the same projection aera 本文对某卷弧尾翼弹气动特性进行了系统研究,主要内容与结论为: 1 .将卷弧翼按照相同投影面积的平板翼进行工程估算,得到升力系数、阻力系数、俯仰力矩系数、俯仰阻尼导数、滚转阻尼导数曲线。
Based on the mechanism of slipstream interaction , described in this thesis is firstly the interaction of the propeller slipstream with the wing 、 fuselage and horizontal tail . subsequently , the changes in lift 、 drag and pitching moment are derived , giving an engineering model for the prediction of the increments in the aerodynamic characteristics caused by the interference between the propeller slipstream and the other parts of aircraft . this method offers a powerful means to the calculation of the aerodynamic interaction between the propeller and the aircraft , providing reliable data for the design of and aerodynamic calculation on propeller - powered aircraft 本文以滑流干扰的机理为出发点,研究了螺旋桨滑流与飞机机翼、机身、平尾组合体之间的相互影响,推导出滑流引起的飞机升力、阻力和俯仰力矩的变化,给出了滑流干扰对机体气动特性影响的工程估算方法,为研究螺旋桨与飞机部件之间的相互干扰提供了有力的工具,为以螺旋桨发动机为动力的飞机的设计和气动计算提供可靠的依据。
Wind tunnels are essential for research and teaching of aerodynamics ; they provide a major means for discovering and confirming airflow phenomena , exploring and revealing airflow mechanism , seeking and understanding airflow rules , and providing fine aerodynamic configuration and aerodynamic characteristic data for aircraft design . the development of advanced wind tunnel is the prerequisite for t enhancing accuracy and standard of wind tunnel experiments , playing an important role in improving product aerodynamic design 风洞是空气动力学科研和教学的必要条件，是发现和确认流动现象、探索和揭示流动机理、寻求和了解流动规律，以及为飞行器设计提供优良的气动布局和空气动力学特性数据的主要手段，先进风洞的建设，是提高风洞实验精度及水平的前提，对提高产品的气动设计质量具有重要的作用。
In this paper , in order to find the approaches to reduce the drag levels and enhance the lift - drag ratio for grid fin , the aerodynamic characteristics of the grid fin are calculated with tvd finite volume scheme and wind tunnel tests . according to the complex flow field , a curve - long parameter grid generation technique is applied , and the density of the grid is processed 为适应复杂流场的数值计算，对网格生成方法进行了研究，采用弧长网格生成法进行贴体网格生成，并对网格进行了加密处理，使物面附近网格尽量密些，而在远场使网格尽量稀疏些。
According to the measuremental data of the two ammunications , the anti - designed computation and analysis of aerodynamic characteristic , flight stability , exterior ballistic characteristic for the two ammunications are studied with the advanced methods of the exterior ballistics . using the monte calo algorithm , the statistic mathematical model about ammunication ' s intensity is established and the 1000 miter vertical target intensity and the fall intensity are discussed in detail for the two ammunications . the improval potential and the main technical approachs of these ammunication ' s exterior ballistic performances are presented by compositive optimal algorithm 根据工厂对俄ak130舰炮弹药的测绘数据，利用先进的外弹道数值分析方法对两种弹药的空气动力特性、飞行稳定性特性、外弹道特征量等进行了反设计计算分析；采用montecarlo方法，建立了舰炮弹药密集度性能统计分析数学模型，对两种弹药的立靶密集度和地面密集度进行了详细的计算分析；利用外弹道性能综合优化设计方法对两种弹药的外弹道性能指标的改进潜力和主要技术途径进行了分析。
