升阻比

采用Lagrange乘数优化方法，约束升力系数和机翼翼根弯矩，通过修改机翼+翼梢小翼组合体的结构外形，减小机翼的诱导阻力和形状阻力，提高机翼的展向效率和升阻比的大小。

The Lagrange multipliers optimization method is presented for wing + winglet configuration with constraint for lifting coefficient and wing root bending moment . By shaping the wing with winglet , decrease the sum of induced drag and profile drag , increase span efficiency and lift-drag ratio .

在初始设计空间，响应面方法的结果很差，通过不断缩减设计空间，设计得到了有效的改善，升阻比提高了70%，但需要的计算量远远高于Kriging模型。

While the result of the response surface method is very poor in the original design space . This status is amended effectively through reducing the design space continuously and the lift-drag ratio increases by 70 % , however the calculation cost is far more expensive than the Kriging method .

根据P－M理论，计算了五种三翼面飞机和试验模型的诱导阻力因子、升阻比以及翼面升力比等。

On the basis of P-M theory , the calculations are made for the induced drag factor , the ratio of lift to drag , and the ratio of lift in surfaces on five kinds of three-surface planes and test models .

在MATLAB环境下，求解了最大化升阻比的单目标优化问题和具有两个冲突目标（最小化铰链力矩并且最大化平均操纵效率）的多目标优化问题。

An optimal problem maximizing lift to drag ratio and a multi objective optimization problem minimizing hinge moment while maximizing average operating efficiency , are solved using the algorithms presented here in the MATLAB environment .

通过相关的计算可知：降低陶瓷基质的电阻率、提高陶瓷基质的升阻比，防止金属的氧化、降低结构因子有利于获得低室温电阻率、大升阻比的PTC复合材料。

And it will improve the properties of composites such as lowering the resistivity of ceramic matrix and Ni , increasing the resistivity-jump of ceramic matrix , decreasing the structural factor .

结果表明，（Sr，Pb）TiO3的居里温度较理论计算值稍有偏移。典型陶瓷样品的电阻升阻比为4.2，V型特性明显。

Results indicated that Curie temperature of ( Sr , Pb ) TiO 3 deviates slightly from calculated value , and lg (Δ R max / R min ) is 4 2 V type characteristic is remarkable .

针对Lockheed-AFOSRWingB的亚临界和超临界算例结果表明，厚度的非线性分布和负的扭角会改善机翼流场的流动状态，使机翼的升阻比得到提高，优化设计方法是可行的。

The subcritical and supercritical computation of Lockheed-AFOSR wing B cases show that nonlinear distribution of thickness and negative twist angle could ameliorate the condition of flow field around the wing , which leads to higher lift-to-drag ratio , the optimization method is effective .

实验表明，与普通Al2O3相比，纳米Al2O3能显著提高PTC陶瓷的性能：温度系数增大60%，常温电阻降低20%，耐压增大13%，升阻比增大近1个数量级。

The experiments show that compared with conventional alumina powder , nano alumina can significantly improve the properties of PTC material by increasing temperature coefficient 60 % , lowering room temperature resistance 20 % , increasing breakdown voltage 13 % , and jump range about one order , respectively .

在Y掺杂的钛酸锶铅中，分别添加过量PbO、SiO2、ZrO2制备之半导体陶瓷样品，在居里点（约120℃）以上具有强的PTC效应，升阻比接近5个数量级。

Y-doped Sr_ ( 0.5 ) Pb_ ( 0.5 ) TiO_3 semiconductor ceramics were prepared by adding the excess PbO , SiO_2 and ZrO_2 , respectively . The ceramics sintered exhibit the strong PTC effect and the jump range is of the order of five when temperature is > tC .

BTT飞行器因其气动稳定性好，升阻比大等优点受到国内外广泛关注，很多学者都对BTT飞行器的相关技术进行研究，其中制导控制问题已经成为主要的研究问题之一。

In recent years , BTT missile receives extensive attentions , considering its outstanding aerodynamic stability and high lift-to-drag ratio . The techniques pertinent to BTT missile are investigated by many researchers . Among these techniques , guidance and control is one of the most important .

以M6机翼为初始机翼，进行了多目标、多约束的气动-结构优化设计，优化后的机翼具有较好的气动-结构综合性能，升阻比增加了9.25%，而重量减轻了4.84%；

M6 wing is chosen as the base wing . The design results show that the lift-to-drag ratio has increased by 9.25 % and the structural weight has reduced by 4.84 % , the response surface methodology is accurate enough to satisfy the engineering requirement .

本文主要介绍小升阻比载人飞船返回舱的配平气动特性。

This paper introduces the trim aerodynamic characteristics of re-entry modules .

连接翼布局气动特性优于常规翼布局，特别是最大升阻比可达12以上，失速迎角超过30°。

Maximum lift-drag ratio is 12.The stalling angle is greeter then 30 degree .

本文在进行高超音速气动分析时，应用修正的牛顿碰撞理论和一阶平面面元法计算运载器的气动特性，求出它的配平攻角和升阻比；

Newtonian Impact Theory and One-order Panel Method are used for hypersonic aerodynamic analysis .

分析提出了进一步提高该乘波体气动布局升阻比的有效途径。

The favorable method of improving the lift-drag ratio of the figuration is brought forward .

通过对比阻力以及升阻比可知三角翼型的阻力比较大。

Through comparing the resistance force and maximum lift-to-drag ratio knowable triangle airfoil resistance is larger .

翼型抖振边界是仅次于升阻比的一项重要气动指标。

Airfoil buffet boundary is an important aerodynamic parameter which is second only to the lift-drag ratio .

优化结果表明，优化后的机翼具有较好的气动&结构综合性能，升阻比增加了而重量有所减轻：模型精度满足设计要求，拟合误差均不超过1%。

The design results show that lilt-to - drag ratio was increased and structural weight was reduced .

提高叶轮机械叶片的升阻比，是改进叶轮机械气动性能的重要途径。

Increasing the lift drag ratio of turbine blade is an effective way for improving turbines aerodynamic characteristics .

着重研究了改变升阻比和再入角对再入轨道的影响。

We put stress upon investigating the effect of changing lift drag ratio and reentry angle on reentry orbit .

设计风机的一个首要目标是使叶片上具有大的升阻比。

A prime objective in wind turbine design is for the blade to have a high lift to drag ratio .

由数值分析得到采用最大升阻比的滑翔策略可获得最佳滑翔增程效果。

The results show that the best effect of glide extended-rang is obtained with the adoption of maximum lift-drag ratio slide .

通过优化分析可以得到保证最大滑翔距离的最优滑翔策略近似等价于导弹以最大升阻比飞行。

The strategy to guarantee maximum glide distance is equivalent to keep maximum shift-resistance ratio in the flight from the optimization analysis .

分析了涡襟翼的涡流运动特点及其升阻比增大的机理；

The characteristics of vortex flow movement induced by vortex flaps and the principle of increasing lift-drag ratio of the wing are analyzed .

计算得到的升阻比与实验数据吻合很好。

The value of the lift-to-drag ratio obtained with the present computations was in good agreement with those experiment data reported in the literature .

本文研究了增加叶轮机械叶片气动效率的新机理，也是一种新的节能技术，即在叶片某部位增加局部粗糙度可以增加叶片的升阻比，从而提高叶片的气动效率。

The new theorem of increasing aerodynamic efficiency of turbomachinery blade is studied , which is also a new technology for energy economization ; i.

飞行器设计的一个重要目标，就是要优化流场分布，减少阻力，增加升力，提高飞行器的升阻比。

A primary objective of aircraft design is optimizing the distributing of the flow , drag reduction , increasing lift and the lift-drag ratio .

在设计点附近选取合适的半基准圆锥激波角并考虑粘性影响时，可得到乘波体最大升阻比为3.36；

The biggest lift drag ratio 3.36 considering viscous effects is obtained at Mach 6 when a proper base conical shock wave angle is chosen .

在小升阻比情况下，正、负升力再入时轨道特性、有效载荷基本相同。

Under the circumstances of smaller lift-drag-ratio , the two kinds of reentry trajectories produced by positive lift and negative lift are approximately the same .

为延长无人机留空时间，加大航程和提高升限，可采用加装翼尖小翼的方法使无人机的升阻比有所提高。

Modification of winglet is adopted to raise the lift-drag ratio of the UAV for extension endurance , for enlarge range and for increase ceiling .