The longitudinal stability, the aerodynamic characteristics of lift-drag ratio, flight trimming and linearization of the nonlinear model in the full envelope are all analyzed, concluding that the ASV is longitudinal static unstable under subsonic and hypersonic flight conditions and the lift coefficient and lift-drag ratio are smaller.
针对空天飞行器飞行包线范围大，质量变化快，飞行动力学特性复杂等特点，研究和改进了空天飞行器的仿真模型，该模型具有质量时变特性和推力矢量功能；分析了空天飞行器的纵向静稳定性、升阻比气动特性，表明在亚声速和高超声速飞行阶段 ASV 呈现纵向静不稳定特性，全包线内升力系数、升阻比较常规飞行器小；对全包线非线性模型进行了配平和线性化分析，得到了 ASV 的配平包线，通过仿真验证表明，与常规飞行器相比，纵向长/短周期模态基本相同，而横侧向出现多种新的模态。
A wide front fascia with a large, forward-facing grille opening, a splitter along the bottom and wheel opening extensions along the sides to provide aerodynamic downforce A cold air scoop in front of the hood that integrates an air inlet system for the engine The trailing edge of the front wheel opening is radiused to achieve improved drag, but protects the body finish with a tough molding, and a large air extractor is located behind the wheel A fixed-roof bodystyle optimizes body rigidity and mass Wider rear fenders with flares cover the massive rear tires and a brake cooling scoop in front of the wheels visually balances the fender extractor A tall rear spoiler houses the CHMSL on the top of the rear fascia 10-spoke wheels (18-inch, front; 19-inch, rear) Four larger stainless steel exhaust outlets New-design Chevrolet Corvette Z06 badging on the carbon fiber front fenders
宽阔的前仪表的大，面向前方格栅启用，底部和侧面的轮开放扩展拆分为空气下压力的一个寒冷的空气罩前面铲，整合为一个航空发动机进气道系统的尾部前轮的边缘radiused开放，实现改善阻力，但保护的强硬成型身体结束，和一个大型空气提取的背后是车轮固定屋顶bodystyle优化车身刚性和群众更广泛的耀斑位于后翼子板覆盖大规模的后方轮胎和刹车冷却的车轮前面铲视觉平衡挡泥板提取一个高大的后扰流器房子的后方筋膜十名高位刹车灯，以车轮（18英寸，前，19英寸，后）四较大的不锈钢排气口新设计的雪佛兰克尔维特Z06的碳纤维前挡泥板徽章
It is very important to reduce the aerodynamic drag and noise for traveling vehicles.
减低汽车行驶中的空气阻力、抑制其行驶时的气动噪声具有十分重要的意义。
The lift/drag ratio is 30.8% higher, and the aerodynamic performance under the off-working condition is also significantly improved; The flow control with optimal smart body surface of airfoil under the pitching motion is achieved. Not only the lift/drag ratio is increased, but also the hyteresis cycle is reduced remarkablely.
在非设计攻角下和非设计雷诺数下的气动特性也比原翼型有了较大提高；实现了二维翼型在不可压非定常流动中作俯仰振荡运动时动态失速的最优智能物面流动控制，不但提高了升阻比，而且使迟滞环明显缩小。
After that, the generation and optimization methods for the integrated waveriders are also constructed, and the formal and aerodynamic characteristics of the ordinary C shape waveriders are examined in combine with the further CFD results, and their connections and differences with the basic waveriders are analyzed, which show, the integrated waveriders suffer severe lift-to-drag ratio losses with much gains in the volume and longitudinal stability.
以上述研究为基础，进一步建立了一体化乘波体的生成和优化设计方法，同样结合CFD数值计算，对最常见且性能折中的C型一体化乘波体的外形及气动力特性进行了研究，分析了它与基本乘波体在性能方面的重要区别。结果表明，一体化乘波体的升阻比较基本乘波体下降较多，但容积大大增加，且具有良好的纵向稳定性。
The aerodynamic characteristics of low Reynolds number, and the influence to laminar separation bubble and lift-drag ratio are analyzed.
分析了低雷诺数小型飞机的空气动力特性，包括对升阻比和分离气泡的影响。
While it has increased in nearly every dimension, overall aerodynamic advancement was aided by a specially designed undertray, resulting in a segment-topping 0.32 coefficient of drag.
虽然它在几乎每个方面的增加，总体空气动力学的发展是得益于特殊设计的undertray，导致技术领域的突破0.32的阻力的系数。
Results demonstrated that aerodynamic drag coefficients of the wheel and the whole car change as the number and area of holes increases.
得出随着辐板上开孔个数和面积的增加车轮的气动阻力和汽车总气动阻力系数的变化规律。
The main reasons caused aerodynamic drag is clarified.
得到了汽车的风阻系数，清楚地了解了外流场特点和气动特性。
In the end, the effect of coefficient of aerodynamic drag, rolling resistance coefficient and efficiency of powertrain on fuel economy are analysed.
最后，分析了风阻系数、迎风面积、滚动阻力系数和传动系效率对整车燃油经济性的影响，为ISG-MHV进一步的优化设计提供了依据。
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.
为了探索减少格栅翼阻力和提高升阻比的方法和途径，本论文对格栅翼的气动力特性进行了数值模拟和风洞实验研究。
Based on N- S equation of the compressible viscous fluid and k-ε turbulence model, aerodynamic drag and lift coefficient at different running speeds and air pressure pulse of two trains meeting each other of the TR08 train and other three Maglev trains were calculated with finite volume method.
利用可压缩粘性流体的N- S方程和k-ε双方程湍流模型，采用有限体积法对包括TR08磁浮列车在内的4种高速磁浮列车周围流场进行数值模拟，得出磁浮列车在不同运行速度下的气动阻力系数、升力系数及列车以430 km/h运行时的交会压力波幅值。
Based on the results, it is helped to analyze the mechanism of external flow, the relationship between flow characteristic and aerodynamic drag, the main reasons causing aerodynamic drag, and provide basic reference to the reduction of truck aerodynamic drag.
通过对运输车的实车测量，在PRO／ENGINEER中构建三维CAD简化模型，并根据空气动力学的一般规律，设计了四种针对运输车特殊厢体顶蓬的导流罩以及整车空气动力学附加装置优化模型。
Looking as aerodynamic as a side-by-side Frigidaire, it still manages to cut through the air with relatively little wind noise due to its 0.35 coefficient of drag.
展望作为空气动力学作为并排北极，但仍设法穿过空气相对少风的噪音，因为它0.35的阻力系数。
The static pressure distribution curve in open-jet wind tunnel test section is obtained by calculation, which provides a basis for high-speed train aerodynamic drag measuring test model to select length and location. Aerodynamic drag of different scale model in wind tunnel and full scale model at open line condition is obtained by numerical computation. The numerical results are analyzed for the blockage effect, influence of Reynolds number, and pressure gradient in test section. Consequently a reasonable range of test model scale for studied wind tunnel is obtained.
首先，计算得到开口式风洞测试段的静压系数分布曲线，为高速列车气动阻力测量试验模型的长度选择以及摆放位置提供依据；其次，通过数值计算得到全尺寸模型列车在明线运行时，以及不同比例的模型列车在风洞中运行工况下的气动阻力信息，并从阻塞效应和雷诺数的变化，以及风洞试验段内静压分布的影响这3个方面对列车模型的气动阻力结果进行分析，得到在所研究风洞中较合理的列车缩比模型比例选取范围。
Some important charactics were found in the experiments. It is shown that internal acoustic excitations can reduce aerodynamic drag and suppress aerodynamic noise.
得出了一些重要规律，表明内部声激励可以减低汽车的空气阻力、抑制气动噪声。
As well, due to the high terminal velocity, the aerodynamic drag penalty would be particularly great.
同时，由于高终端速度，气动阻力的刑罚将是特别大。
The institutions pay much attention to it stemmed from the fact. Oblique wing aircraft can decrease high transonic and low supersonic flight drag, and improves the aerodynamic efficiency in high speed flight.
因此斜置机翼飞机能够有效地减小飞机在高跨音速和低超音速时的飞行阻力，提高飞机超音速飞行的气动效率。
High speed train; aerodynamic drag; wind tunnel test
高速列车；空气阻力；风洞试验
To provide more references for the selection of high-speed train scale model for wind tunnel testing, the effect of different scale model of a high-speed train on aerodynamic drag obtained from wind tunnel test is studied by Computational Fluid Dynamics.
为给高速列车气动阻力风洞试验模型选取提供更多的参考依据，通过计算流体力学(Computational Fluid Dynamics，CFD)方法，研究不同比例的高速列车缩比模型对气动阻力风洞试验结果的影响。