查询词典 aerodynamic force

An unsteady aerodynamic model based on Fourier analysis is developed in the frequency domain with the theory of system identification and the experimental data of large amplitude harmonic oscillation. This unsteady aerodynamic mathematical model is used to extract dynamic derivatives, and the meaning of a time-lag loop is analyzed.

应用系统辨识理论，利用纵向大振幅非定常气动力实验数据，在频率域内建立了基于Fourier变换法的非定常气动力数学模型，并发展了一种获取常规动导数的仿真实验方法，分析了迟滞环的物理意义。

In the computation of aerodynamic forces, the present work is based on the work of Morino et al., but the following aspects are improved:(1) In computing the steady transonic aerodynamic load, the steady transonic nonlinear integral equation is solved by relaxation-iteration method in this thesis, instead of solving the time dependent transonic nonlinear integral equation, so that the computing time is saved greatly;(2) The influence coeifficients represented by volume integral are transformed to surface integral by using the Gaussian Theorem, so the analytical form of these coeifficients can be obtained and this leads to be more convenient to analyse and compile computer program;(3) The shock capturing method is used in every time step in present work, no shock moving term is added in the integral equation, so that it is more convenient and simpler to treat.

在气动力计算方面，本文基于Morino等人的工作，作了如下几方面的改进：（1）在计算定常跨音速流场（作为非定常绕流计算的初场）时，本文采用松驰迭代法直接求解跨音速定常非线性积分方程，而不是采用时间相关法求解非定常非线性积分方程，这样大大节省了计算机时；（2）将以体积分形式出现的影响系数化为面积分，并获得解析公式，这样便于分析和编写程序；（3）对运动的激波，本文通过在每一个时间步长上采用激波捕捉法而得到，而不是在积分方程中附加激波运动项，因而处理起来简单方便得多。

This thesis is based on the developing project of "Testing and research on the related technology of the aerodynamic effect in the high speed railway tunnel", which is from the national railway department and also based on the project of "The research on the micro-pressure wave and tunnel hood around the gate of the tunnel in YuHuai railway with the speed of 200km/h",which is from the second surveyed and design institute of China Railways. Research on the lucubration of tunnel aerodynamic effects mechanism and corresponding alleviation measure was carried out.

本文以铁道部科技研究开发计划项目《高速铁路隧道空气动力学相关技术的研究与试验测试》和铁道部第二勘测设计院《遂渝铁路时速200公里隧道洞口微压波及缓冲设施研究》为依托，结合我国国情，对隧道空气动力学效应的作用机制和其减缓措施进行研究。

To analyze quantitatively the performances of genetic algorithms used in aerodynamic optimization design and the effects of the skills introduced, the numerical test planform for genetic optimization models is set up on Microsoft Fortran Powerstation. As applications, several aerodynamic optimization designs for airfoil, wing and aircraft are carried out to testify the adaptation of genetic optimization models.

建立了以Fortran Powerstation 4.0为开发环境的各种遗传优化模型的数值试验平台，对各遗传算法、改进技术及其优化模型的性能（优化质量和优化效率、可操作性）进行定量分析，并在此基础上建立了翼型、机翼和全机的优化设计软件系统。

Methods For different body aerodynamic roll angles, proper wind-tunnel test schemes were selected and trigonometric series were used for aerodynamic interpolation.

按照不同的气动滚转角，进行合理有限的吹风，然后以三角周期函数进行插值。

The static aerodynamic characteristics of the projectile are computed using the software of CFD, the results of the numerical simulation are agreement with the engineering calculation, this verifies that the results of the static aerodynamic characteristics of WAF from engineering calculation are satisfactory.

应用CFD软件对弹静态气动特性进行数值计算，数值计算结果与工程估算结果吻合较好，说明卷弧翼的静态气动特性可以通过平板翼进行估算。

The results show that, for the first with no headwall, when there is no crosswind, it has small front face areas, so the aerodynamic resistance is the least. Since the second and the third have headwall, the front face areas are large, so they have bigger aerodynamic resistance. Under the condition of crosswind, as the third design option has the highest side beam, the area of positive pressure at the upwind is bigger, and the area of negative pressure is smaller when the bigger eddy area appears, so the side forces become larger. The first has the least side forces; the overturning moment of the first is the least.

研究结果表明：在无横风情况下，方案一中没有端墙，迎风面积较小，受到的气动阻力最小，方案二和三中平车有端墙，迎风面积较大，受到的气动阻力也较大；有横风情况下，方案三中平车侧梁较高，车体迎风面正压区较大，而背风侧产生较大的涡流区，在此区域内压力较小，故其横向力较大，方案一中平车侧梁没有加高，受到的横向力最小；方案一中平车倾覆力矩最小，稳定性最好。

The procedure and aerodynamic design process of the CPU fan are embodied into parametric design and numerical simulation software utilizing VB language as well as axial-flow fan aerodynamic design software,which can generate high quality HEXA mesh automatically.

采用VB开发了CPU轴流风扇空气动力设计软件和风扇参数化设计模拟软件，使用者只需输入风扇的基本结构参数，便可由程序自动生成高质量的六面体网格，能自动进行批处理模拟和结果后处理。

As previously stated by Hucho [1], the longer attached flow Tab.3 Aerodynamic coefficients may result in improved aerodynamic quality.

作为 先前所哲罗[ 1 ] ，再附流 tab.3气动系数可能会导致改善气动品质。

The effect of static aeroelastic distortion to the aerodynamic characteristic for a real high-aspect ratio sweepforward wing of composite material under different load statuses was analyzed. The integrated design method combined aerodynamic with structural was adopted in this analysis using associated computational fluid dynamics program FLUENT and computational structual dynamics program NASTRAN.

针对－真实复合材料大展弦比前掠机翼，采用气动／结构一体化的分析方法，利用计算流体动力学软件FLUENT和计算结构动力学软件NASTRAN联合求解，研究了在不同载荷情况下大展弦比柔性机翼静气动弹性变形对机翼气动特性的影响。

Hanna: That's over now, isn't it?

都结束了，对吗

You must be ill. You look so pale.

你一定是病了，你的脸色苍白。