涡

The characteristic curve and primary parameter of different rotation speed has been obtained.

尤其是在涡轴发动机和一些弹用涡喷发动机中，离心式压气机更是不可缺少的关键部件之一。

I am a careless boy she is a chary girl.

我是一个粗心的男孩，她是一个细心地女孩，我是一个硕士生男孩，她是一个本科生女孩，我是一个喜欢吃辣的男孩，她是一个喜欢吃甜的女孩，我是一个喜欢璇子的男孩，她是一个喜欢曦曦的女孩，我是一个来自涡阳的男孩，她是一个来自来自涡阳的女孩。

An improved model of curved vortex element on the circular arc for rotor free wake analysis is presented.

涡元技术是尾迹分析的基础，本文第二章改进了先前的曲涡元模型。

Therefore, the moist potential vorticity analysis associated with the mesoscale convective system was researched in the paper, so as to reveal the moist potential characteristics of mesoscale convective system in typhoon circulation. The results showed that, during the generation stage, convective instability characterized by MPV1 was a favorable condition for forming MCS, while the vorticity which was caused by the slantwise isentropic surface and the vertical shear of the horizontal wind characterized by MPV2 was an inspiring mechanism. The specific process was that, the atmosphere exhibited the feature of strong convective instability at the low level of convection areas and the southeast areas, which included plenty of erratic energy. The slantwise ascended the stream transfer the erratic energy to northwest, where the stratification stability was small. As decreased, the cyclonic vorticity increased. On the other hand, the vorticity caused by the slantwise isentropic surface and the vertical shear of the horizontal wind inspired the release of convective instability and as a result that the MCS formed. During the development stage, the cyclonic vorticity increased quickly with the persistent decreasing of . Meanwhile, the inclination of isentropic linewas bigger than the absolute momentum line at middle level, which exhibited the feature of conditional symmetric instability , then the conditional symmetric instability was forced to release by the vorticity resulted from the slantwise isentropic surface and the vertical shear of horizontal wind, and the MCS developed.

结果表明，在对流形成阶段，MPV1即对流不稳定为MCS的形成提供背景不稳定条件，由MPV2即湿等熵面的倾斜和水平风的垂直切变而引起的涡旋发展作为强迫机制：MCS形成的区域及东南区域中低层是强对流不稳定层，蕴含丰富的不稳定能量，倾斜上升运动把对流不稳定区具有强不稳定能量的暖湿空气向西北中层的中性层结区输送，由于的减小，气旋性涡度增强，有利于形成对流，另一方面，由于湿等熵面倾斜和低空急流加强而引起的涡旋发展作为一种强迫机制激发对流不稳定能量得到释放，从而形成对流；在对流系统地发展阶段，由于低层的对流不稳定性进一步减弱，进一步减小，气旋性涡度进一步增强，有利于MCS的增强，中层等θe 线的倾斜度比绝对动量M 等值线的倾斜度大，对应有条件对称不稳定区域，满足条件对称不稳定条件，在湿等熵面倾斜和台风低空急流作用下引起的涡旋发展强迫对称不稳定能量释放，从而使得对流得以维持和加强。

The results show that the increasing Marangoni number will lead to more nonlinear distribution of temperature field, but streamfunction of the cell center; vorticity on the wall and peak value of velocity diminish first, then increase, finally lose stability. The thermocapillary convection in the whole liquid zone appears to get stronger along with the augmentation of Prantal number. The effect of increasing of Biot number on temperature and flow fields is not obvious although the convection is strengthened a little. As increasing the aspect ratio A, thermocapillary convection induced by temperature gradient and liquid viscosity becomes stronger.

结果表明：温度场的非线性分布随着Ma数的增大而加剧，但对流涡胞中心流函数、壁面涡量和轴向、径向速度峰值并不象温度场随着Ma数的增大而单调增大，而是先减小，然后增大，最后失稳，表明Ma数对热毛细对流的影响比较复杂，针对不同的物理模型，会导致完全不同的流态；Pr数愈大，流体的热扩散能力在粘性扩散与热扩散能力之比中愈占支配地位，当Ma数一定时，热毛细对流随Pr数的增大在整个液体区域内有增强的趋势；Bi数增大，热毛细对流有所增强，但不甚明显；A的增大使得由温度梯度和流体粘性诱导的热毛细对流随之增强。

The purpose of flow visualization research of sections in double delta wing is to uncover the mechanism of vortex interference and structure,from this research,we can control the vortex and provide lasis for constructing numerical model.

进行双三角翼翼面流动显示研究的目的是为了揭示前、后翼脱体涡的干扰机理和详细结构，进而达到控制表面涡分离的目的，并为计算流体力学建立数学模型提供依据。

They found that the shift from a vortex-ring to a continuous-vortex gait depended on sufficient forward velocity to provide airflow over the wing during the upstroke similar to that during the downstroke.

他们发现，转移，从涡环一个连续涡步态依赖于足够的前进速度提供的气流，机翼在upstroke类似，在

Based on the theory of large eddy simulation and the method of VOF , the initial breakup process of fuel liquid jet, which eject from the nozzle exit at the time scale of micro-second level, is investigated. The mechanism of primary atomization is analyzed, and the initial breakup model of liquid jet is presented. By modeling and numerical simulation of atomization for a diesel nozzle under the given conditions, the initial umbrella-like spray shapes are obtained, which fits better with the experimental results. Meanwhile, the droplets secondary breakup process, such as leeward RT breakup, dumbbell-like breakup and droplets coalescence, etc. are exhibited visually.

基于大涡模拟LES理论和VOF方法，考察了燃油喷雾初始时刻即时间尺度为微秒级的液柱破碎过程，分析了初始破碎的机理，给出了该时间尺度下液柱初始破碎过程的模型；通过对一特定条件下的柴油机喷油器的建模和喷雾过程的大涡数值模拟，获得了液柱初始时刻"伞状头部"的喷雾形态，所得计算结果与相应的试验数据符合较好；数值模拟还直观地展现了液滴背风RT破碎、哑铃型破碎以及液滴的聚集融合等液滴的二次雾化过程。

The numerical results show that, after the hot intrusion reaches the cold wall, some accumulates in the cold top corner, since the cold boundary layer flow cannot entrain all of the hot intrusion.

结果表明：当热入侵流抵达腔体冷壁后，由于冷壁无法卷入所有的热入侵流，热入侵流在冷上角堆积并产生一个反向流动，在冷壁边界层附近形成一个顺时针涡，该涡在浮力效应驱动下可返回热壁，并在腔体的冷热壁之间形成了腔体尺度的流体振荡，即内重力波。

The results showed that erectness of coupling pattern between upper-layer jet and low jet and a divergence area, which came forth in right of upper-layer jet provide favorable surrounding conditions. The most intensive moisture convergence, the strongest ascending movement and the most instable convection stratification all occurred in the rainfall center. The rainstorm occurred at the warm and wet side of the negative value center of the moist potential vorticity and relative MPV, which had certain indicative significance for the forecast of rainstorm areas.

结果表明：高低空急流的优势配置，耦合形势的建立以及高空急流右侧的强辐散场的存在为暴雨的发生提供了有利的环境条件；暴雨区中上升运动和水汽辐合均大于周围区域，中低层为对流不稳定层结；暴雨区位于湿位涡和湿相对位涡负值中心附近偏暖湿气流一侧，对暴雨落区预报有一定的指示意义。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。