风速脉动

在北京北郊气象铁塔（325m高）的160m高度上释放平衡气球，用双经纬仪定位的方法得到拉格朗日表示法的风速脉动资料。

Velocity fluctuations in the Lagrangian frame have been observed by using a double-theodolite system to track balanced balloons released at the height of 160m of the 325m tower which is located on the north suburb of Beijing .

大气边界层风速脉动的分形模拟

Fractal Representation of Wind Speed Fluctuation in Atmospheric Boundary Layer

风沙流中风速脉动对输沙量的影响

Effect of Wind Speed Fluctuation on Sand Transport Rate

算例表明即使需要模拟非常长的风速脉动时间历程，方法仍具有非常高的精度和效率。

A numerical example shows this method is high efficiency and accuracy even when very long sequences are simulated .

大气边界层风场中风速脉动导致的风压改变在设计时已不容忽视。

The influence on wind pressure by turbulence in boundary layer wind field can not be ignored in design .

此外，作物残茬、秸秆和牧草等粗糙元的高度、密度及直立性均对下垫面的空气动力学粗糙度、摩阻速度及风速脉动有一定影响。

In addition , the height , density and perpendicularity of remnant stubble , straws and grass had influence on aerodynamic roughness and wind velocity fluctuation on different underlying surfaces .

当迎角一定，来流风速脉动幅值一定时，随着风速脉动频率的增加，气动特性在大迎角时的变化也比较大。

When the incidence and oscillating amplitude of velocity are constant , the oscillation of the aerodynamic characteristics is increased with the oscillating frequency of velocity in large angle of attack .

本文使用渤海石油平台观测的超声波风速脉动资料，计算了强风条件下二维风速和风向的最大熵谱和傅立叶功率谱。

Using the data set of the wind fluctuation measured by the ultrasonic anemometer on the oil platform in the Bohai Sea , the spectra of 2-dimension wind velocity and wind direction were calculated .

接着研究了两种微型飞行器在水平阵风环境下的非定常气动特性，分别给出了模型迎角和风速脉动频率变化对微型飞行器气动特性的影响。

The unsteady aerodynamic characteristics of the two MAVs in horizontal gust are studied . Both the effects of the angle of attack of the two MAVs and the oscillating frequency of velocity are discussed .

桥梁风致抖振是由于自然风风速脉动引起的一种受迫振动，会造成悬索桥摆动而影响悬索桥的行车舒适度以及造成构件的疲劳破坏。

Wind-induced buffeting is one kind of forced vibration due to the natural wind velocity wavering , Wind-induced buffeting may arouse the suspension bridge vibration to affect the comfort in driving and make component damaged by fatigue failure .

研究了脉动风速和脉动风压的概率统计表达方法，给出了有关公式。

Trembling Pulse Probability statistic expressions of pulse wind velocity and pressure are investigated .

实验还研究了不同床层高度和流化风速对脉动特性的影响，并定性分析了优化流化脉动，减少声损失的途径。

The effect of fluidizing bed height and the gas velocity on the pulsating characteristics were also investigated .

研究了风速、脉动强度和静止床层高度对水冷夹套的换热系数的影响；

The influences of the air velocity , pulsating intensity and static bed height to the heat transfer coefficient were studied .

在时间上，风速的脉动以及随风频繁脱落的涡系都会引起塔架结构的振动。

In time , wind speed fluctuation and frequent shedding of vortices wind will cause the vibration of the tower structure .

节点数确定后，我们进行了脉动风速与实测脉动风速的比较，结果表明两者相吻合。

After the number of nodes is determined , we conduct a comparison of the numerical fluctuating wind speed and the experimental fluctuating wind speed . The results show well consistency .

烟羽浓度预测，采用了粒子随机游走大气扩散模式，该模式所依赖的平均风速和湍流脉动参数均来自非静力平衡、完全可压缩的动力学模式。

The plume prediction is on the basis of a particle random walking model , in which the average wind transport speed and the parameters of turbulent fluctuation are source from the non-hydrostatic , full compressible dynamics model .

在混合粒径时，我们同样先确定了节点数，然后比较了实测脉动风速和模拟脉动风速，结果与单一粒径的结果相同。

For mixed particle size bed , we obtain the number of nodes firstly . Then we compare the experimental fluctuating wind speed and the simulation fluctuating wind speed . The results is identical with that of the single size bed .

其次，讨论了近地风的有关特性，包括风的组成、平均风剖面平均风速的特性以及脉动风速的特性等，简要介绍了风引起的灾害。

Secondly , this paper presents a general discussion of the basic wind characteristics and the disaster induced by wind .

风对桥上列车的运行安全有很大影响：在平均风速为30~40m/s的脉动风作用下，车辆的轮重减载率、脱轨系数和倾覆系数超标，必须给予足够的重视。

The running safety of the train is much affected by wind : Under the wind of 30-40m / s , the offload factors , derail factors and overturn factors of the train vehicles exceed the allowances , to which great attention should be paid .

首先，求解常微分方程的初值问题，得到无脉动时颗粒的临界起动风速，并且调整脉动强度，求解不同脉动强度对颗粒起动平均风速的影响。

Firstly , solving the initial boundary value of differential equation in order to get the threshold wind velocities of particles when there is no fluctuation , and then adjusting fluctuation intensity , getting the influence of different fluctuation intensity to get the threshold wind velocities of particles .

根据随机振动理论，采用Davenport风速谱模拟作用在结构上的风荷载，绘制出脉动风速及脉动风荷载时程曲线。

According to the random vibration theory , the Davenport wind speed spectrum simulation effect of wind load on structures , and map the fluctuating wind load time history curve .

基于4个台风过程中的长时间序列风速、风方向观测数据，分析研究了近地台风的湍流积分尺度和脉动风速谱等脉动特性。

In this paper , the fluctuation characteristics of turbulence integral scale and wind speed spectra of near ground typhoon are studied based on the four sets of long time record of wind speed and wind direction during the passages of typhoon .